Files
nexus/sreweekly/articles/473/04-evaluating-mysql-lock-scheduling-performance-cats-vs-fifo.html
2026-09-12 17:23:01 +08:00

2997 lines
146 KiB
HTML
Raw Blame History

This file contains ambiguous Unicode characters
This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
<meta name="viewport" content="width=device-width, initial-scale=1">
<meta name="description" content="This article shows that MySQL’s CATS algorithm offers only a small performance gain over FIFO once deadlock logging interference is removed.">
<meta name="keywords" content="MySQL, CATS, Performance">
<meta property="og:description" content="This article shows that MySQL’s CATS algorithm offers only a small performance gain over FIFO once deadlock logging interference is removed.">
<meta property="og:site_name" content="dzone.com">
<meta property="og:title" content="Evaluating MySQL Lock Scheduling Performance: CATS vs FIFO">
<meta property="og:url" content="https://dzone.com/articles/mysql-cats-vs-fifo-performance">
<meta property="og:image" content="https://dz2cdn1.dzone.com/storage/article-thumb/18328221-thumb.jpg">
<meta property="og:type" content="article">
<meta name="twitter:site" content="@DZoneInc">
<meta name="twitter:image" content="https://dz2cdn1.dzone.com/storage/article-thumb/18328221-thumb.jpg">
<meta name="twitter:card" content="summary_large_image">
<meta name="twitter:description" content="This article shows that MySQL’s CATS algorithm offers only a small performance gain over FIFO once deadlock logging interference is removed.">
<meta name="twitter:title" content="Evaluating MySQL Lock Scheduling Performance: CATS vs FIFO">
<meta name="referrer" content="origin-when-cross-origin">
<meta name="google-site-verification" content="kndbhxcupfEqWmZclhCpB6vlgOs7QSmx2UHAGGnP2mA">
<meta name="df-verify" content="df0d76632b4543">
<link rel="icon" type="image/x-icon" href="https://dz2cdn1.dzone.com/themes/dz20/images/favicon.png">
<link rel="image_src" href="https://dz2cdn1.dzone.com/storage/article-thumb/18328221-thumb.jpg">
<link rel="canonical" href="https://dzone.com/articles/mysql-cats-vs-fifo-performance">
<title>Evaluating MySQL Lock Scheduling Performance: CATS vs FIFO</title>
<link rel="preload" href="https://dz2cdn1.dzone.com/themes/dz20/font/fontello.woff?11773374" as="font" type="font/woff" crossorigin="anonymous">
<link rel="stylesheet" media="all" href="https://dz2cdn1.dzone.com/themes/dz20/ftl/icons.css">
<link rel="stylesheet" media="all" href="https://dz2cdn1.dzone.com/themes/dz20/lib/static/bootstrap/bootstrap.min.css">
<link rel="stylesheet" media="all" href="https://dz2cdn1.dzone.com/themes/dz20/ftl/article/global.css">
<link rel="stylesheet" media="all" href="https://dz2cdn1.dzone.com/themes/dz20/ftl/header-updated/styles.css">
<style>
:root {
--xs-size: 2px;
--sm-size: 5px;
--md-size: 10px;
--lg-size: 15px;
--xl-size: 25px;
--sm-border-size: 8px;
--sm-font-size: 13px;
--sm-plus-font-size: 16px;
--md-font-size: 18px;
--lg-font-size: 22px;
--xl-font-size: 26px;
}
/* Display Quick-Access Classes */
.display-none { display: none; }
.display-block { display: block; }
.display-inline { display: inline; }
.display-inline-block { display: inline-block; }
/* Margin Quick-Access Classes */
.m-xs { margin: var(--xs-size); }
.m-sm { margin: var(--sm-size); }
.m-md { margin: var(--md-size); }
.m-lg { margin: var(--lg-size); }
.m-xl { margin: var(--xl-size); }
.mt-xs, .my-xs { margin-top: var(--xs-size); }
.mr-xs, .mx-xs { margin-right: var(--xs-size); }
.mb-xs, .my-xs { margin-bottom: var(--xs-size); }
.ml-xs, .mx-xs { margin-left: var(--xs-size); }
.mt-sm, .my-sm { margin-top: var(--sm-size); }
.mr-sm, .mx-sm { margin-right: var(--sm-size); }
.mb-sm, .my-sm { margin-bottom: var(--sm-size); }
.ml-sm, .mx-sm { margin-left: var(--sm-size); }
.mt-md, .my-md { margin-top: var(--md-size); }
.mr-md, .mx-md { margin-right: var(--md-size); }
.mb-md, .my-md { margin-bottom: var(--md-size); }
.ml-md, .mx-md { margin-left: var(--md-size); }
.mt-lg, .my-lg { margin-top: var(--lg-size); }
.mr-lg, .mx-lg { margin-right: var(--lg-size); }
.mb-lg, .my-lg { margin-bottom: var(--lg-size); }
.ml-lg, .mx-lg { margin-left: var(--lg-size); }
.mt-xl, .my-xl { margin-top: var(--xl-size); }
.mr-xl, .mx-xl { margin-right: var(--xl-size); }
.mb-xl, .my-xl { margin-bottom: var(--xl-size); }
.ml-xl, .mx-xl { margin-left: var(--xl-size); }
.ml-auto, .mx-auto { margin-left: auto; }
.mr-auto, .mx-auto { margin-right: auto; }
.mt-auto, .my-auto { margin-top: auto; }
.mb-auto, .my-auto { margin-bottom: auto; }
.my-none, .mt-none { margin-top: 0 !important; }
.mx-none, .mr-none { margin-right: 0 !important; }
.my-none, .mb-none { margin-bottom: 0 !important; }
.mx-none, .ml-none { margin-left: 0 !important; }
/* Padding Quick-Access Classes */
.p-xs { padding: var(--xs-size); }
.p-sm { padding: var(--sm-size); }
.p-md { padding: var(--md-size); }
.p-lg { padding: var(--lg-size); }
.p-xl { padding: var(--xl-size); }
.pt-xs, .py-xs { padding-top: var(--xs-size); }
.pr-xs, .px-xs { padding-right: var(--xs-size); }
.pb-xs, .py-xs { padding-bottom: var(--xs-size); }
.pl-xs, .px-xs { padding-left: var(--xs-size); }
.pt-sm, .py-sm { padding-top: var(--sm-size); }
.pr-sm, .px-sm { padding-right: var(--sm-size); }
.pb-sm, .py-sm { padding-bottom: var(--sm-size); }
.pl-sm, .px-sm { padding-left: var(--sm-size); }
.pt-md, .py-md { padding-top: var(--md-size); }
.pr-md, .px-md { padding-right: var(--md-size); }
.pb-md, .py-md { padding-bottom: var(--md-size); }
.pl-md, .px-md { padding-left: var(--md-size); }
.pt-lg, .py-lg { padding-top: var(--lg-size); }
.pr-lg, .px-lg { padding-right: var(--lg-size); }
.pb-lg, .py-lg { padding-bottom: var(--lg-size); }
.pl-lg, .px-lg { padding-left: var(--lg-size); }
.pt-xl, .py-xl { padding-top: var(--xl-size); }
.pr-xl, .px-xl { padding-right: var(--xl-size); }
.pb-xl, .py-xl { padding-bottom: var(--xl-size); }
.pl-xl, .px-xl { padding-left: var(--xl-size); }
.py-none, .pt-none { padding-top: 0 !important; }
.px-none, .pr-none { padding-right: 0 !important; }
.py-none, .pb-none { padding-bottom: 0 !important; }
.px-none, .pl-none { padding-left: 0 !important; }
/* Flex Quick-Access Classes */
.flex {
display: flex;
}
.flex-column {
display: flex;
flex-direction: column;
}
.flex-column-reverse {
display: flex;
flex-direction: column-reverse;
}
.flex-row {
display: flex;
flex-direction: row;
}
.flex-row-reverse {
display: flex;
flex-direction: row-reverse;
}
.flex-wrap {
flex-wrap: wrap;
}
.flex-grow {
flex-grow: 1;
}
.align-center { align-items: center; }
.align-end { align-items: flex-end; }
.content-center {
align-content: center;
}
.justify-center { justify-content: center; }
.justify-start { justify-content: flex-start; }
.justify-end { justify-content: flex-end; }
.justify-around { justify-content: space-around; }
.justify-between { justify-content: space-between; }
.justify-evenly { justify-content: space-evenly; }
.gap-sm { gap: var(--sm-size); }
.gap-md { gap: var(--md-size); }
.gap-lg { gap: var(--lg-size); }
.gap-xl { gap: var(--xl-size); }
/* Display Quick-Access Classes */
.inline-block { display: inline-block; }
/* Font Quick-Access Classes */
.font-xl { font-size: var(--xl-font-size); }
.font-lg { font-size: var(--lg-font-size); }
.font-md { font-size: var(--md-font-size); }
.font-sm-plus { font-size: var(--sm-plus-font-size); }
.font-sm { font-size: var(--sm-font-size); }
.font-strike { text-decoration: line-through; }
.font-underline { text-decoration: underline; }
.font-overline { text-decoration: overline; }
.font-italic { font-style: italic; }
.font-bold { font-weight: bold; }
.font-black { color: #000000; }
.font-white { color: #ffffff; }
.font-gray { color: var(--brand-gray-text); }
.font-danger { color: var(--header-dropdown-button-bg-danger); }
.font-center { text-align: center; }
.no-wrap { white-space: nowrap; }
/* Consistent headings between h and non-h tags */
.heading {
margin-top: 0;
margin-bottom: var(--md-size);
}
.heading.font-xl { line-height: var(--xl-font-size); }
.heading.font-lg { line-height: var(--lg-font-size); }
.heading.font-md { line-height: var(--md-font-size); }
.heading.font-sm-plus { line-height: var(--sm-plus-font-size); }
.heading.font-sm { line-height: var(--sm-font-size); }
/* Font Clamp Quick-Access Classes */
.line-clamp,
.line-clamp-2,
.line-clamp-3,
.line-clamp-4,
.line-clamp-5 {
display: -webkit-box;
-webkit-line-clamp: 4;
-webkit-box-orient: vertical;
overflow: hidden;
text-overflow: ellipsis;
}
.line-clamp-2 { -webkit-line-clamp: 2 !important; }
.line-clamp-3 { -webkit-line-clamp: 3 !important; }
.line-clamp-4 { -webkit-line-clamp: 4 !important; }
.line-clamp-5 { -webkit-line-clamp: 5 !important; }
/* User-Select Quick-Access Classes */
.select-none { user-select: none; }
/* Position Quick-Access Classes */
.absolute { position: absolute; }
.relative { position: relative; }
.float-left { float: left; }
.float-right { float: right; }
.pos-top { top: 0; }
.pos-right { right: 0; }
.pos-bottom { bottom: 0; }
.pos-left { left: 0; }
.va-top { vertical-align: top; }
.va-middle { vertical-align: middle; }
.va-bottom { vertical-align: bottom; }
/* Transition Quick-Access Classes */
.trans-linear-quick {
transition: all 0.15s linear;
}
/* Background Quick-Access Classes */
.bg-gray { background: #cccccc; }
.bg-white { background-color: white; }
.bg-none { background: none; }
/* Border Quick-Access Classes */
.border-gray { border: 1px solid #cccccc; }
.tab-pane.border-gray { border: 1px solid #ddd; }
.no-border, .border-none { border: none !important; }
.bt-none { border-top: none !important; }
.br-none { border-right: none !important; }
.bb-none { border-bottom: none !important; }
.bl-none { border-left: none !important; }
/* Border Radius Quick-Access Classes */
.round-t-sm, .round-tl-sm { border-top-left-radius: var(--sm-border-size); }
.round-t-sm, .round-tr-sm { border-top-right-radius: var(--sm-border-size); }
.round-b-sm, .round-bl-sm { border-bottom-left-radius: var(--sm-border-size); }
.round-b-sm, .round-br-sm { border-bottom-right-radius: var(--sm-border-size); }
.round-sm { border-radius: var(--sm-border-size); }
.round-fully { border-radius: 50%; }
/* Misc Quick-Access Classes */
.haikei {
position: relative;
background-image: url('https://dz2cdn1.dzone.com/themes/dz20/images/polygon-scatter-haikei-shapes.svg');
background-repeat: no-repeat;
background-size: cover;
}
.haikei:before {
content: '';
position:absolute;
top: 0;
left: 0;
width: 100%;
height: 100%;
background-color: var(--color-event-background);
z-index: -1;
}
.margin-auto-center {
display: block;
margin-left: auto;
margin-right: auto;
}
.flex-auto-center {
display: flex;
margin-left: auto;
margin-right: auto;
}
.mw-1100 { max-width: 1100px; }
.mw-1300 { max-width: 1300px; }
.full-width { width: 100%; }
.h-separator {
background-color: #cccccc;
height: 1px;
width: 100%;
margin: 5px auto;
}
.no-spacing {
margin: 0 !important;
padding: 0 !important;
}
.inherit-color { color: inherit; }
.inherit-decoration { text-decoration: inherit; }
/* Table Quick-Access Classes */
.table-border-gray tr:not(:last-child) {
border-bottom: 1px solid #cccccc;
}
table.full-width tr td:last-child {
width:100%;
}
/* Animation Quick-Access Classes */
@keyframes anim-spin {
0% { transform: rotate(0deg); }
100% { transform: rotate(359deg); }
}
.anim-spin {
display: inline-block;
animation: anim-spin 2s infinite linear;
}
.hov-pointer { cursor: pointer; }
.hov-brighten:hover { filter: brightness(1.2); }
.hov-darken:hover { filter: brightness(0.95); }
.hov-underline:hover { text-decoration: underline; }
/* Small tweaks related to components when using these styles */
.nav-tabs {
border-bottom: none;
}
.tab-content > .flex-column.active,
.tab-content > .flex-row.active {
display: flex;
}
/* Alpine components with x-cloak should not be visible by default until conditionals kick in */
[x-cloak] { display: none !important; }
</style>
<link rel="stylesheet" media="all" href="https://dz2cdn1.dzone.com/themes/dz20/ftl/alpine-components/modal.css">
<script defer src="https://dz2cdn1.dzone.com/themes/dz20/lib/alpinejs/3.13.2/cdn.min.js"></script>
<script>
document.addEventListener('alpine:init', () => {
Alpine.store('article', {
id: null,
engagement: {
open: false,
page: 1,
users: [],
additional: true,
loading: false,
initializing: false,
unauthorized: false,
enqueued: null,
dequeued: null,
reset() {
this.open = false;
this.page = 1;
this.users.splice(0);
this.additional = true;
this.loading = false;
this.initializing = false;
this.enqueued = null;
this.dequeued = null;
},
enqueue(user) {
this.dequeued = null;
this.enqueued = user;
},
dequeue(user) {
this.enqueued = null;
this.dequeued = user;
},
add(user) {
this.users.push(user);
this.enqueued = null;
},
remove(user) {
const index = this.users.findIndex(u => u.id === user.id);
if (index !== -1) {
this.users.splice(index, 1);
}
this.dequeued = null;
},
contains(user) {
return this.users.filter(u => u.id === user.id).length;
}
}
});
Alpine.effect(() => {
const store = Alpine.store('article');
if (!store.engagement.additional && store.engagement.enqueued) {
if (!store.engagement.contains(store.engagement.enqueued)) {
store.engagement.add(store.engagement.enqueued);
}
}
});
Alpine.effect(() => {
const store = Alpine.store('article');
if (store.engagement.page && store.engagement.dequeued) {
store.engagement.remove(store.engagement.dequeued);
}
})
});
</script></head>
<body x-data>
<div class="skybox skybox-closeBtn dz_skybox" data-gpt-slot="skybox" id="div-gpt-ad-1435246566686-99"></div>
<header id="ftl-header">
<div class="header-top">
<div class="header-container">
<div class="pull-left logo-container">
<div class="logo">
<a class="inner" href="/">
<picture>
<source srcset="https://dz2cdn1.dzone.com/themes/dz20/images/dz_logo_2021_cropped.webp" type="image/webp">
<source srcset="https://dz2cdn1.dzone.com/themes/dz20/images/dz_logo_2021_cropped.png" type="image/png">
<img src="https://dz2cdn1.dzone.com/themes/dz20/images/dz_logo_2021_cropped.png" width="181" height="56" alt="DZone">
</picture>
</a>
</div>
</div>
<div class="pull-right login-and-search">
<div id="authenticated-block" class="logged-in">
<div class="welcome-back">Thanks for visiting DZone today,</div>
<div id="user-header" class="user-info">
<button class="user-avatar">
<span id="header-username" class="username"></span>
<img id="header-avatar" src="" alt="user avatar">
</button>
<div id="user-dropdown" class="browse-user-menu">
<div class="user-content">
<a id="header-user-plug" href="#" class="user-description"></a>
<a id="header-user-edit" href="#" class="edit-profile">Edit Profile</a>
</div>
<ul class="user-actions">
<li id="first-user-action">
<a id="header-dropdown-manage-email" href="#">Manage Email Subscriptions</a>
</li>
<li>
<a href="/articles/how-to-submit-a-post-to-dzone?utm_source=DZone&utm_medium=user_dropdown&utm_campaign=how_to_post">
How to Post to DZone
</a>
</li>
<li>
<a href="/articles/dzones-article-submission-guidelines">
Article Submission Guidelines
</a>
</li>
</ul>
<div class="bottom">
<a href="/users/logout.html" class="sign-out">Sign Out</a>
<a id="dropdown-view-profile" href="#" class="view-profile">View Profile</a>
</div>
</div>
</div>
<div class="post-content">
<button id="post-button" class="post-content--button">
<span class="post-class">Post</span>
<i class="icon-plus"></i>
</button>
<div id="post-menu" class="posting-links">
<div class="posting-links-menu">
<ul>
<li>
<img src="https://dz2cdn1.dzone.com/themes/dz20/images/dz-postarticle.svg" width="15" height="18" style="width: 15px; height: 18px;">
<a href="/content/article/post.html">Post an Article</a>
</li>
<li>
<a id="drafts-link" href="#">Manage My Drafts</a>
</li>
</ul>
</div>
</div>
</div>
</div>
<div id="unauthenticated-block">
<div class="dz-intro">Over 2 million developers have joined DZone.</div>
<div class="mobile-invisible sign-in-join">
<a href="/users/login.html">Log In</a>
<span class="dz-intro-span">/</span>
<a href="/static/registration.html">Join</a>
</div>
<a class="join-icon" href="/users/login.html" aria-label="User">
<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="lucide svg-user lucide-user-icon lucide-user">
<path d="M19 21v-2a4 4 0 0 0-4-4H9a4 4 0 0 0-4 4v2"></path>
<circle cx="12" cy="7" r="4"></circle>
</svg>
</a>
</div>
<script>
document.addEventListener('alpine:init', () => {
Alpine.data('searchDrawer', () => ({
open: false,
query: '',
minCharsMet: false,
toggleVisibility() {
this.open = !this.open;
if (this.open) {
this.$nextTick(() => {
this.$refs.query.focus();
});
}
},
updateSearchValue() {
if (!this.query || !this.query.length || this.query.length < 3) {
this.minCharsMet = false;
return;
}
this.minCharsMet = true;
localStorage.setItem('ls.searchValue', this.query);
},
searchSite() {
if (this.minCharsMet) {
window.location = '/search';
}
}
}));
});
</script>
<div class="headerSearch" x-data="searchDrawer()" x-cloak>
<button class="btn-search dropdown-toggle" x-on:click="toggleVisibility()" aria-label="Search">
<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="lucide svg-search lucide-search-icon lucide-search">
<path d="m21 21-4.34-4.34"></path>
<circle cx="11" cy="11" r="8"></circle>
</svg>
</button>
<template x-teleport=".header-container">
<div id="search-drawer" x-show="open" x-on:click.outside="open = false" x-transition>
<div class="search-input">
<input type="text"
placeholder="Search"
autofocus="autofocus"
x-model="query"
x-ref="query"
x-on:input.change="updateSearchValue()"
x-on:keyup.enter="searchSite()"
>
<button x-on:click="searchSite()" x-bind:disabled="!minCharsMet">
<span>Search</span>
</button>
</div>
<div class="search-footer">
Please enter at least three characters to search
</div>
</div>
</template>
</div>
</div>
</div> </div>
<div class="header-bottom">
<div class="header-bottom-container">
<a class="resource-link" href="/refcardz">Refcards</a>
<a class="resource-link" href="/trendreports">Trend Reports</a>
<div class="resource-link link-menu">
<a href="/events">Events</a>
<a href="/events/video-library">Video Library</a>
</div>
</div>
</div>
<nav class="header-menu-bar">
<div class="header-menu resource-category">
<a href="/refcardz">Refcards</a>
</div>
<div class="header-menu-separator resource-category-separator"></div>
<div class="header-menu resource-category">
<a href="/trendreports">Trend Reports</a>
</div>
<div class="header-menu-separator resource-category-separator"></div>
<div class="header-menu resource-category no-bottom-radius" data-click-activation>
<p class="menu-label">Events</p>
<div class="header-menu-items">
<div class="header-menu-columns">
<a class="header-menu-item" href="/events">View Events</a>
<a class="header-menu-item" href="/events/video-library">Video Library</a>
</div>
</div>
</div>
<div class="header-menu zone-menu" data-click-activation>
<p class="menu-label">Zones <i class="icon-down-dir icon-closed"></i><i class="icon-right-dir icon-open"></i></p>
<div class="header-menu-items">
<div class="header-menu-columns">
<div class="header-menu-column-item">
<a class="header-menu-item" href="/culture-and-methodologies">Culture and Methodologies</a>
<a class="header-menu-item" href="/agile">Agile</a>
<a class="header-menu-item" href="/career-development">Career Development</a>
<a class="header-menu-item" href="/methodologies">Methodologies</a>
<a class="header-menu-item" href="/team-management">Team Management</a>
</div>
<div class="header-menu-column-item">
<a class="header-menu-item" href="/data-engineering">Data Engineering</a>
<a class="header-menu-item" href="/ai-ml">AI/ML</a>
<a class="header-menu-item" href="/big-data">Big Data</a>
<a class="header-menu-item" href="/data">Data</a>
<a class="header-menu-item" href="/databases">Databases</a>
<a class="header-menu-item" href="/iot">IoT</a>
</div>
<div class="header-menu-column-item">
<a class="header-menu-item" href="/software-design-and-architecture">Software Design and Architecture</a>
<a class="header-menu-item" href="/cloud-architecture">Cloud Architecture</a>
<a class="header-menu-item" href="/containers">Containers</a>
<a class="header-menu-item" href="/integration">Integration</a>
<a class="header-menu-item" href="/microservices">Microservices</a>
<a class="header-menu-item" href="/performance">Performance</a>
<a class="header-menu-item" href="/security">Security</a>
</div>
<div class="header-menu-column-item">
<a class="header-menu-item" href="/coding">Coding</a>
<a class="header-menu-item" href="/frameworks">Frameworks</a>
<a class="header-menu-item" href="/java">Java</a>
<a class="header-menu-item" href="/javascript">JavaScript</a>
<a class="header-menu-item" href="/languages">Languages</a>
<a class="header-menu-item" href="/tools">Tools</a>
</div>
<div class="header-menu-column-item">
<a class="header-menu-item" href="/testing-deployment-and-maintenance">Testing, Deployment, and Maintenance</a>
<a class="header-menu-item" href="/deployment">Deployment</a>
<a class="header-menu-item" href="/devops-and-cicd">DevOps and CI/CD</a>
<a class="header-menu-item" href="/maintenance">Maintenance</a>
<a class="header-menu-item" href="/monitoring-and-observability">Monitoring and Observability</a>
<a class="header-menu-item" href="/testing-tools-and-frameworks">Testing, Tools, and Frameworks</a>
</div>
<div class="header-menu-column-item sponsored">
<a class="header-menu-item" href="javascript:void(0)">Partner Zones</a>
<a class="header-menu-item" href="/hubs/build-ai-agents-that-are-ready-for-production/">Build AI Agents That Are Ready for Production</a>
</div>
</div>
</div>
</div>
<div class="header-menu parent-category" tabindex="1">
<a href="/culture-and-methodologies">Culture and Methodologies</a>
<div class="header-menu-items">
<a class="header-menu-item" href="/agile">Agile</a>
<a class="header-menu-item" href="/career-development">Career Development</a>
<a class="header-menu-item" href="/methodologies">Methodologies</a>
<a class="header-menu-item" href="/team-management">Team Management</a>
</div>
</div>
<div class="header-menu-separator parent-category-separator"></div>
<div class="header-menu parent-category" tabindex="2">
<a href="/data-engineering">Data Engineering</a>
<div class="header-menu-items">
<a class="header-menu-item" href="/ai-ml">AI/ML</a>
<a class="header-menu-item" href="/big-data">Big Data</a>
<a class="header-menu-item" href="/data">Data</a>
<a class="header-menu-item" href="/databases">Databases</a>
<a class="header-menu-item" href="/iot">IoT</a>
</div>
</div>
<div class="header-menu-separator parent-category-separator"></div>
<div class="header-menu parent-category" tabindex="3">
<a href="/software-design-and-architecture">Software Design and Architecture</a>
<div class="header-menu-items">
<a class="header-menu-item" href="/cloud-architecture">Cloud Architecture</a>
<a class="header-menu-item" href="/containers">Containers</a>
<a class="header-menu-item" href="/integration">Integration</a>
<a class="header-menu-item" href="/microservices">Microservices</a>
<a class="header-menu-item" href="/performance">Performance</a>
<a class="header-menu-item" href="/security">Security</a>
</div>
</div>
<div class="header-menu-separator parent-category-separator"></div>
<div class="header-menu parent-category" tabindex="4">
<a href="/coding">Coding</a>
<div class="header-menu-items">
<a class="header-menu-item" href="/frameworks">Frameworks</a>
<a class="header-menu-item" href="/java">Java</a>
<a class="header-menu-item" href="/javascript">JavaScript</a>
<a class="header-menu-item" href="/languages">Languages</a>
<a class="header-menu-item" href="/tools">Tools</a>
</div>
</div>
<div class="header-menu-separator parent-category-separator"></div>
<div class="header-menu parent-category" tabindex="5">
<a href="/testing-deployment-and-maintenance">Testing, Deployment, and Maintenance</a>
<div class="header-menu-items">
<a class="header-menu-item" href="/deployment">Deployment</a>
<a class="header-menu-item" href="/devops-and-cicd">DevOps and CI/CD</a>
<a class="header-menu-item" href="/maintenance">Maintenance</a>
<a class="header-menu-item" href="/monitoring-and-observability">Monitoring and Observability</a>
<a class="header-menu-item" href="/testing-tools-and-frameworks">Testing, Tools, and Frameworks</a>
</div>
</div>
<div class="header-menu-separator parent-category-separator"></div>
<div class="header-menu parent-category sponsored" tabindex="6">
<a href="javascript:void(0)">Partner Zones</a>
<div class="header-menu-items sponsored">
<a class="header-menu-item" href="/hubs/build-ai-agents-that-are-ready-for-production/">Build AI Agents That Are Ready for Production</a>
</div>
</div>
<div class="header-menu-separator parent-category-separator"></div>
</nav>
</header>
<script>
const csrf = {
parameter: 'TH_CSRF',
header: 'X-TH-CSRF',
token: '2141305913694494082'
}; // set csrf for auth-status script
</script>
<script>
addEventListener('DOMContentLoaded', function() {
handleRedirects();
handleMenus();
handleMobileMenuHeights();
handleGotoLinks();
});
function isHidden(element) {
try {
return window.getComputedStyle(element).display === 'none';
} catch (_) {
return false;
}
}
function getLink(element) {
if (element.hasAttribute('data-goto')) {
return element.getAttribute('data-goto');
}
return element.href;
}
function isLeftClick(event) {
if (event.altKey || event.shiftKey) {
return false;
} else if ('buttons' in event || 'which' in event) {
return event.buttons === 1 || event.which === 1;
} else {
return (event.button === 1 || (event.type === 'click'));
}
}
function handleRedirects() {
const redirections = [...document.querySelectorAll('[data-activate-menu]'), ...document.querySelectorAll('[data-click-target]')];
redirections.forEach(function(element) {
const menuSelector = element.getAttribute('data-activate-menu') || element.getAttribute('data-click-target');
const redirectingElement = document.querySelector(menuSelector);
if (redirectingElement) {
element.style.cursor = 'pointer';
const redirect = function(e) {
if (redirectingElement.hasAttribute('href') || redirectingElement.hasAttribute('data-goto')) {
if (redirectingElement.hasAttribute('data-new-window') || e.ctrlKey || e.metaKey) {
window.open(getLink(redirectingElement), '_blank');
} else {
window.open(getLink(redirectingElement), '_self');
}
} else {
const evt = new e.constructor(e.type, e);
redirectingElement.dispatchEvent(evt);
}
};
element.addEventListener('mouseup', redirect);
element.addEventListener('mousedown', (e) => e.preventDefault());
element.addEventListener('click', (e) => e.preventDefault());
}
});
}
function handleMenus() {
const menuElements = [
...document.querySelectorAll('.header-menu > a'),
...document.querySelectorAll('.header-menu > p.menu-label')
];
let scrollYMemory = -1;
function scrollToMemory() {
if (scrollYMemory !== -1) {
setTimeout(function() {
window.scrollTo(0, scrollYMemory);
scrollYMemory = -1;
}, 10);
}
}
function hideMenus() {
// unfocus menus & items, and set the menus to non-visible.
menuElements.forEach(function (element) {
element.blur();
element.parentElement.blur();
element.parentElement.classList.remove('menu-opened');
const menuItems = element.parentElement.querySelector('.header-menu-items');
if (menuItems) {
menuItems.style.display = 'none';
}
});
const wasHidden = document.body.style.overflowY === 'hidden';
document.body.style.overflowY = 'auto';
if (wasHidden) {
scrollToMemory();
}
}
function isEventOutsideMenu(e) {
return e.target.closest && !e.target.closest('.header-menu') && !e.target.closest('[data-activate-menu]');
}
// Handle mobile menu toggling
menuElements.forEach(function(element) {
const menu = element.parentElement;
const headerItems = menu.querySelector('.header-menu-items');
const menuEntries = headerItems ? headerItems.querySelectorAll('.header-menu-item') : [];
const focus = function() {
menu.focus();
menu.classList.add('menu-opened');
if (headerItems) {
headerItems.style.display = 'block';
}
if (menu.classList.contains('zone-menu')) {
scrollYMemory = window.scrollY;
document.body.style.overflowY = 'hidden';
} else {
scrollYMemory = -1;
}
};
const unfocus = function() {
menu.blur();
menu.classList.remove('menu-opened');
if (headerItems) {
headerItems.style.display = 'none';
}
const wasHidden = document.body.style.overflowY === 'hidden';
document.body.style.overflowY = 'auto';
if (wasHidden) {
scrollToMemory();
}
};
const toggleMenuVisibility = function(e) {
if ((e.type === 'click' || e.type === 'mouseup') && !isLeftClick(e)) {
e.preventDefault();
return;
}
const hidden = isHidden(headerItems);
if (menu.hasAttribute('data-click-activation')) { // handle click activated toggling
if (hidden) {
hideMenus(); // hide other open menus first
focus();
} else {
unfocus();
}
e.preventDefault();
} else if (hidden) {
hideMenus(); // hide other open menus first
focus();
e.preventDefault(); // prevent 'click' event from firing when menu is hidden
}
};
element.addEventListener('touchend', toggleMenuVisibility);
element.addEventListener('mouseup', toggleMenuVisibility);
// Add hover events to non-click-activated menus, even though CSS should cover it.
if (!menu.hasAttribute('data-click-activation')) {
menu.addEventListener('mouseover', function () {
hideMenus(); // hide other open menus first
focus();
});
menu.addEventListener('mouseout', function (e) {
if (isEventOutsideMenu(e)) {
unfocus();
}
});
}
// Hide menu when child is clicked
menuEntries.forEach(function(menuEntry) {
const linkToItem = function(e) {
if (e.type === 'mousedown' || e.type === 'click') {
e.preventDefault();
return;
}
if (e.type === 'mouseup' && !isLeftClick(e)) {
e.preventDefault();
return;
}
window.open(getLink(menuEntry), (e.ctrlKey || e.metaKey) ? '_blank' : (menuEntry.target || '_self'));
unfocus();
e.preventDefault();
};
const linkToMobileItem = function(e) {
if (e.type === 'touchstart') {
menuEntry.setAttribute('data-touchmove', false);
} else if (e.type === 'touchmove') {
menuEntry.setAttribute('data-touchmove', true);
} else if (e.type === 'touchend' && (!menuEntry.hasAttribute('data-touchmove') || menuEntry.getAttribute('data-touchmove').toLowerCase() === 'false')) {
window.open(getLink(menuEntry), (e.ctrlKey || e.metaKey) ? '_blank' : (menuEntry.target || '_self'));
unfocus();
e.preventDefault();
}
};
menuEntry.addEventListener('mousedown', linkToItem);
menuEntry.addEventListener('mouseup', linkToItem);
menuEntry.addEventListener('click', linkToItem);
menuEntry.addEventListener('touchstart', linkToMobileItem);
menuEntry.addEventListener('touchmove', linkToMobileItem);
menuEntry.addEventListener('touchend', linkToMobileItem);
});
});
function hideIfNonMenuBounds(e) {
if (isEventOutsideMenu(e)) {
hideMenus();
}
}
addEventListener('mousemove', hideIfNonMenuBounds);
addEventListener('touchend', hideIfNonMenuBounds);
addEventListener('mouseup', hideIfNonMenuBounds);
addEventListener('mousedown', hideIfNonMenuBounds);
addEventListener('click', hideIfNonMenuBounds);
}
function handleMobileMenuHeights() {
function setAppHeight() {
document.documentElement.style.setProperty('--app-height', window.innerHeight + 'px');
}
addEventListener('resize', function() {
setAppHeight();
});
setAppHeight();
}
function handleGotoLinks() {
// Add anchor mimicking to elements with data-goto attributes
// This addresses SEO concerns of linking to noindex pages by allowing JS to handle the URL
const anchorElements = document.querySelectorAll('*[data-goto]');
anchorElements.forEach((anchorElement) => {
anchorElement.addEventListener('mouseover', () => {
anchorElement.style.cursor = 'pointer';
anchorElement.style.textDecoration = 'underline';
});
anchorElement.addEventListener('mouseout', () => {
anchorElement.style.cursor = 'unset';
anchorElement.style.textDecoration = 'unset';
});
anchorElement.addEventListener('mouseup', (e) => {
e.preventDefault();
});
anchorElement.addEventListener('mousedown', (e) => {
e.preventDefault();
});
anchorElement.addEventListener('click', (e) => {
e.preventDefault();
const anchorHref = anchorElement.getAttribute('data-goto');
if (anchorElement.hasAttribute('data-new-window') || e.ctrlKey || e.metaKey) {
window.open(anchorHref, '_blank');
} else {
window.open(anchorHref, '_self');
}
});
});
}
</script><script>
const authenticatedBlock = document.querySelector('#authenticated-block');
const unauthenticatedBlock = document.querySelector('#unauthenticated-block');
let authenticated = {
isAuthenticated: false,
isAdmin: false,
user: {
id: null,
name: null,
url: null,
profileImage: null,
}
};
fetch('/services/internal/data/articles-getAuthenticationStatus', {
headers: {
'Accept': 'application/json'
}
})
.then(function (result) {
return result.json()
})
.then(function (result) {
const res = result.result.data
if (!res.authenticated) {
unauthenticatedBlock.classList.add('shown')
} else {
authenticated.user.id = res.id;
authenticated.user.name = res.realName;
authenticated.user.url = res.profileUrl;
authenticated.user.profileImage = res.avatar;
authenticated.user.jobTitle = res.jobTitle;
authenticated.user.companyName = res.companyName;
bindProps('#header-username', null, null, (res.firstName || res.username), null)
bindProps('#header-avatar', null, res.avatar, null, null)
bindProps('#header-user-plug', res.profileUrl, null, res.realName, null)
bindProps('#header-user-edit', '/users/' + res.id + '/edit.html', null, null, null)
bindProps('#header-dropdown-manage-email', '/newsletters/' + res.id + '/manage.html', null, null, null)
bindProps('#dropdown-view-profile', res.profileUrl, null, null, null)
bindProps('#drafts-link', '/users/' + res.id + '/drafts.html', null, null, null)
if (res.isAdmin) {
// Construct backwards so the #after call places elements in the correct order
const firstUserAction = document.querySelector('#first-user-action')
const adminConsoleItem = document.createElement('li')
const adminConsoleLink = createLink('/dzone/staff/index.html', 'Admin Console')
adminConsoleItem.appendChild(adminConsoleLink)
firstUserAction.after(adminConsoleItem)
const moderationItem = document.createElement('li')
const moderationLink = createLink('/moderation/list.html', 'Moderation')
moderationItem.appendChild(moderationLink)
firstUserAction.after(moderationItem)
const bountyModerationItem = document.createElement('li')
const bountyModerationLink = createLink('/moderation/bounties', 'Bounty Moderation')
bountyModerationItem.appendChild(bountyModerationLink)
firstUserAction.after(bountyModerationItem)
}
authenticated.isAuthenticated = res.authenticated;
authenticated.isAdmin = res.isAdmin;
authenticatedBlock.classList.add('shown')
}
}).catch(function (result) {
console.error(result)
})
/**
* Binds different properties to the selected element.
*
* @param selector - Selector to select the element
* @param href - href attribute value
* @param src - src attribute value
* @param innerHTML - innerHTML property value
* @param innerText - innerText property value
*/
function bindProps(selector, href, src, innerHTML, innerText) {
const element = document.querySelector(selector)
if (element) {
if (href) element.href = href
if (src) element.src = src
if (innerHTML) element.innerHTML = innerHTML
if (innerText) element.innerText = innerText
}
}
/**
* Creates a new link element.
*
* @param href - href attribute value
* @param innerText - innerText property value
* @returns {HTMLAnchorElement} The generated link element
*/
function createLink(href, innerText) {
const link = document.createElement('a')
link.href = href
link.innerText = innerText
return link
}
</script><script>
const userHeader = document.querySelector('#user-header')
const userDropdown = document.querySelector('#user-dropdown')
const postDropdown = document.querySelector('#post-button')
const postMenu = document.querySelector('#post-menu')
let userDropdownOpen = false
let postDropdownOpen = false
document.addEventListener('click', function(event) {
if (postDropdown && postDropdown.contains(event.target)) {
setUserDropdown(false)
setPostDropdown(!postDropdownOpen)
} else if (userHeader && userHeader.contains(event.target)) {
setPostDropdown(false)
setUserDropdown(!userDropdownOpen)
} else {
setUserDropdown(false)
setPostDropdown(false)
}
})
function setUserDropdown(value) {
userDropdownOpen = value
if (userDropdownOpen) {
if (userDropdown) {
userDropdown.classList.add('open')
}
} else {
if (userDropdown) {
userDropdown.classList.remove('open')
}
}
}
function setPostDropdown(value) {
postDropdownOpen = value
if (postDropdownOpen) {
if (postMenu) {
postMenu.classList.add('open')
}
} else {
if (postMenu) {
postMenu.classList.remove('open')
}
}
}
</script><script>
document.addEventListener("alpine:init", () => {
Alpine.store('global', {
executeHttp(path, body, method) {
const options = {
method: method,
headers: {
[csrf.header]: csrf.token
}
};
if (method !== 'GET') {
options.body = JSON.stringify(body);
options.headers = {
...options.headers,
'Content-Type': 'application/json; charset=UTF-8'
};
}
return new Promise((resolve, reject) => {
fetch(path, options)
.then(res => {
if (!res.ok) {
reject(res);
} else {
resolve(res);
}
})
.catch(err => reject(err));
});
},
getFromService(path) {
return this.executeHttp(path, null, 'GET');
},
postToService(path, body = {}) {
return this.executeHttp(path, body, 'POST');
},
putToService(path, body = {}) {
return this.executeHttp(path, body, 'PUT');
}
});
});
</script>
<link rel="stylesheet" media="all" href="https://dz2cdn1.dzone.com/themes/dz20/ftl/colors.css">
<link rel="stylesheet" media="all" href="https://dz2cdn1.dzone.com/themes/dz20/ftl/article/styles.css">
<div id="body-container">
<div id="announcement-container-outer">
<div id="announcement-previous">
<i class="icon-angle-left"></i>
</div>
<div id="announcement-next">
<i class="icon-angle-right"></i>
</div>
<div id="announcement-container">
<div class="announcement announcement-count-1"
data-position="1">
<div class="body"><p><strong>Could your team report a vulnerability within 24 hours? </strong>Find out on September 23.</p></div>
<div class="spacer"></div>
<a href="https://cvent.me/O32zXR?utm_source=Announcements&amp;utm_medium=DzoneWeb&amp;utm_campaign=QtGroup-0923" target="_blank">
<button>Assess Your CRA Readiness</button>
</a>
</div>
</div>
</div>
<script type="text/javascript" async>
(function() {
let announcementPosition = 1;
let minAnnouncementPosition = -1;
let maxAnnouncementPosition = -1;
const announcementPrevBtn = document.querySelector('#announcement-previous');
const announcementNextBtn = document.querySelector('#announcement-next');
function withAnnouncements(callback) {
const announcements = document.querySelectorAll('#announcement-container .announcement');
for (let announcement of announcements) {
callback(announcement);
}
}
function initAnnouncementVars() {
document.querySelector(':root').style.setProperty('--mobile-announcement-separator-width', '1px');
withAnnouncements(function(announcement) {
const pos = parseInt(announcement.getAttribute('data-position'));
minAnnouncementPosition = minAnnouncementPosition === -1 ? pos : Math.min(minAnnouncementPosition, pos);
maxAnnouncementPosition = maxAnnouncementPosition === -1 ? pos : Math.max(maxAnnouncementPosition, pos);
});
if (document.querySelector('.announcementBarContainer')) {
document.querySelector(':root').style.setProperty('--body-top-padding', '0');
}
if (maxAnnouncementPosition <= 0) {
document.querySelector(':root').style.setProperty('--body-top-padding', '0');
}
sizeToFullWhenOneEntryOnMobile();
}
function setAnnouncementPosition(position) {
if (window.outerWidth >= 890) {
return; // we do not need to change the position, since we can display everything on desktop.
}
// Make the announcement cyclical
if (minAnnouncementPosition !== -1 && maxAnnouncementPosition !== -1) {
if (position > maxAnnouncementPosition) {
position = minAnnouncementPosition; // overflow to the first announcement
} else if (position < minAnnouncementPosition) {
position = maxAnnouncementPosition; // underflow to the last announcement
}
announcementPosition = position;
}
const shownAnnouncements = [];
let reverseFlex = false; // should only be true when the first and last items are showing
// Now that the position is valid, apply the transforms
withAnnouncements(function(announcement) {
const pos = parseInt(announcement.getAttribute('data-position'));
const isWrapped = position === maxAnnouncementPosition && pos === minAnnouncementPosition; // showing first + last at same time
const doesNextQualify = window.outerWidth >= 500 && (pos === position + 1 || isWrapped);
if (pos === position || doesNextQualify) {
shownAnnouncements.push(announcement);
} else {
announcement.style.display = 'none';
}
announcement.style.opacity = 0.0;
if (isWrapped) {
reverseFlex = true;
}
});
for (let announcement of shownAnnouncements) {
announcement.style.display = 'flex';
announcement.style.opacity = 1.0;
}
const announcementContainer = document.querySelector('#announcement-container');
if (announcementContainer) {
announcementContainer.style.flexDirection = reverseFlex ? 'row-reverse' : 'row';
}
}
function resetAnnouncements() {
announcementPosition = 1;
const announcementContainer = document.querySelector('#announcement-container');
if (announcementContainer) {
announcementContainer.style.flexDirection = 'row';
}
withAnnouncements(function(announcement) {
announcement.style.opacity = 1.0;
announcement.style.display = 'flex';
});
}
function sizeToFullWhenOneEntryOnMobile() {
if (maxAnnouncementPosition <= 2 && announcementPrevBtn && announcementNextBtn) {
announcementPrevBtn.style.display = maxAnnouncementPosition === 2 && window.outerWidth < 500 ? 'flex' : 'none';
announcementNextBtn.style.display = maxAnnouncementPosition === 2 && window.outerWidth < 500 ? 'flex' : 'none';
}
if (maxAnnouncementPosition === 1 && window.outerWidth >= 500 && window.outerWidth < 890) {
document.querySelector(':root').style.setProperty('--mobile-announcement-separator-width', '0');
document.querySelector('#announcement-container .announcement').style.maxWidth = '100%';
}
}
function resetAnnouncementsOnResize() {
announcementPosition = 1; // we want to reset the announcement position every resize
if (window.outerWidth >= 890) { // 4 announcements can be shown (215px * 4) + separator padding
resetAnnouncements();
} else { // if we're still on mobile, set the position to normalize things after resize
setAnnouncementPosition(announcementPosition);
sizeToFullWhenOneEntryOnMobile();
}
}
window.addEventListener('resize', resetAnnouncementsOnResize);
initAnnouncementVars();
setAnnouncementPosition(announcementPosition); // sets the min & max positions as well as initializes transforms
if (announcementPrevBtn) {
announcementPrevBtn.onclick = function() {
setAnnouncementPosition(announcementPosition - 1);
};
}
if (announcementNextBtn) {
announcementNextBtn.onclick = function() {
setAnnouncementPosition(announcementPosition + 1);
};
}
})(); </script>
<div id="ftl-article" class="trending-article-body">
<aside class="trending-sidebar" aria-labelledby="related-sidebar-heading">
<div class="trending">
<h2 id="related-sidebar-heading">Related</h2>
<div class="trending-separator"></div>
<ul>
<li class="item">
<a href="/articles/master-sql-performance-optimization-techniques" class="related-link">Master SQL Performance Optimization: Step-by-Step Techniques With Case Studies</a>
</li>
<li class="item">
<a href="/articles/mysql-80-performance-degradation-analysis" class="related-link">In-Depth Analysis of MySQL 8.0 Performance Degradation</a>
</li>
<li class="item">
<a href="/articles/fine-tuning-mysql-performance-resolving-issues" class="related-link">Fine-Tuning Performance, Resolving Common Issues in FinTech Application With MySQL</a>
</li>
<li class="item">
<a href="/articles/databricks-cache-improves-analytics-workloads" class="related-link">Improving Repeated Analytics Workloads With Databricks Disk Cache</a>
</li>
</ul>
</div>
</aside>
<div class="container-fluid body trending-article-fluid">
<div class="row">
<div class="col-md-12">
<div class="articles-wrap">
<div class="ad-container">
<div id="div-gpt-ad-1435246566686-0" class="ads-billboard-article dz2_article_billboard_new" data-gpt-slot="top"></div>
</div>
<div class="article-stream widget-top-border">
<div class="article-main">
<div class="content-right-images">
<div id="div-gpt-ad-1435246566686-2" class="sidebar-ad dz2_article_halfpage_new" data-gpt-slot="sidebar1"></div>
<div class="trending-separator"></div>
<aside class="trending" aria-labelledby="trending-sidebar-heading">
<h2 id="trending-sidebar-heading">Trending</h2>
<ul>
<li class="item">
<a href="/articles/random-json-node-nuxt" class="trending-link" target="_self">Fetching Information Randomly From JSON Using Node, Nuxt, Express</a>
</li>
<li class="item">
<a href="/articles/ampere-pmu-profiler-microarchitecture" class="trending-link" target="_self">Ampere PMU Profiler: A Guide to Microarchitecture Profiling</a>
</li>
<li class="item">
<a href="/articles/kafka-dashboards-queries" class="trending-link" target="_self">Dashboards and Queries for Apache Kafka</a>
</li>
<li class="item">
<a href="/articles/argocd-safe-deploy" class="trending-link" target="_self">How to Safely Deploy Control-Plane and Data-Plane Changes With Argo CD and Argo Rollouts</a>
</li>
</ul>
</aside>
</div>
<script type="application/ld+json">
{
"@context": "https://schema.org",
"@type": "Article",
"headline": "Evaluating Performance Gains in MySQL Lock Scheduling Algorithms",
"author": [{"image":{"@type":"ImageObject","caption":"Bin Wang","url":"https://secure.gravatar.com/avatar/44bbe0682127fc2cfb1320c6bc6183e5?d=identicon&r=PG"},"@type":"Person","worksFor":{"@type":"Organization","name":"NULL"},"name":"Bin Wang","url":"https://dzone.com/users/5200737/wangbin579.html"}],
"audience": "software developers",
"keywords": "",
"timeRequired": "PT7M",
"commentCount": 0,
"wordCount": "1618",
"accessMode": "textual, visual",
"datePublished": "2025-04-08T00:00:00Z",
"articleSection": "",
"publisher": {
"@type": "Organization",
"name": "DZone",
"url": "https://dzone.com",
"logo": {
"@type": "ImageObject",
"url": "https://dzone.com/themes/dz20/images/dz_logo_2021_cropped.png"
}
},
"articleBody": "Scheduling is crucial in computer system design. The right policy can significantly reduce mean response time without needing faster machines, effectively improving performance for free. Scheduling also optimizes other metrics, such as user fairness and differentiated service levels, ensuring some job classes have lower mean delays than others [1]. MySQL 8.0 uses the Contention-Aware Transaction Scheduling (CATS) algorithm to prioritize transactions waiting for locks. When multiple transactions compete for the same lock, CATS determines the priority based on scheduling weight, calculated by the number of transactions a given transaction blocks. The transaction blocking the most others gets higher priority; if weights are equal, the longest waiting transaction goes first. A deadlock occurs when multiple transactions cannot proceed because each holds a lock needed by another, causing all involved to wait indefinitely without releasing their locks. Comparing CATS and FIFO Performance After understanding the MySQL lock scheduling algorithm, let's examine how this algorithm affects throughput. Before testing, it is necessary to understand the previous FIFO algorithm and how to restore it. For relevant details, refer to the git log explanations provided below. This WL improves the implementation of CATS to the point where the FCFS will be redundant (as often slower, and easy to \"emulate\" by setting equal schedule weights in CATS), so it removes FCFS from the code, further simplifying the lock_sys's logic. Based on the above prompt, restoring the FIFO lock scheduling algorithm in MySQL is straightforward. Subsequently, throughput was tested using SysBench Pareto distribution scenarios with varying concurrency levels in the improved MySQL 8.0.32. Details are provided in the following figure. Figure 1. Impact of CATS on throughput at various concurrency levels. From the figure, it can be seen that the throughput of the CATS algorithm significantly exceeds that of the FIFO algorithm. To compare these two algorithms in terms of user response time, refer to the following figure. Figure 2. Impact of CATS on response time at various concurrency levels. From the figure, it can be seen that the CATS algorithm provides significantly better user response times. Furthermore, comparing deadlock error statistics during the Pareto distribution test process, details can be found in the following figure. Figure 3. Impact of CATS on ignored errors at various concurrency levels. Comparative analysis shows that the CATS algorithm significantly reduces deadlocks. This reduction in deadlocks likely plays a key role in improving performance. The theoretical basis for this correlation is as follows [2]: Under a high-contention setting, the throughput of the target system will be determined by the concurrency control mechanism of the target system: systems which can release locks earlier or reduce the number of aborts will have advantages in such a setting. The above test results align closely with MySQL's official findings. The following two figures, based on official tests [3], demonstrate the significant effectiveness of the CATS algorithm. Figure 4. Comparison of CATS and FIFO in TPS and mean latency: insights from the MySQL blog. Additionally, MySQL's official requirements for implementing the CATS algorithm are stringent. Specific details are provided in the following figure: Figure 5. Requirements of the official worklog for CATS. Therefore, with the adoption of the CATS algorithm, performance degradation should be absent in all scenarios. It seems like things end here, but the summary in the CATS algorithm's paper [1] raises some doubts. Details are provided in the following figure: Figure 6. Doubts about the CATS paper. From the information above, it can be inferred that either the industry has overlooked potential flaws in FIFO, or the paper's assessment is flawed, and FIFO does not have the serious problems suggested. This contradiction highlights a critical problem: one of these conclusions must be flawed; both cannot be correct. Contradictions often present valuable opportunities for in-depth problem analysis and resolution. They highlight areas where existing understanding may be challenged or where new insights can be gained. This time, testing on the improved MySQL 8.0.27 revealed significant bottlenecks under severe conflicts. The perf screenshot is shown in the following figure: This time, testing on the improved MySQL 8.0.27 revealed a large number of error logs in the MySQL error log file. Below is a partial screenshot: Figure 7. Partial screenshot of numerous error logs. Continuing the analysis of the corresponding code, the specifics are as follows: C++ void Deadlock_notifier::notify(const ut::vector&lt;const trx_t *&gt; &amp;trxs_on_cycle, const trx_t *victim_trx) { ut_ad(locksys::owns_exclusive_global_latch()); start_print(); const auto n = trxs_on_cycle.size(); for (size_t i = 0; i &lt; n; ++i) { const trx_t *trx = trxs_on_cycle[i]; const trx_t *blocked_trx = trxs_on_cycle[0 &lt; i ? i - 1 : n - 1]; const lock_t *blocking_lock = lock_has_to_wait_in_queue(blocked_trx-&gt;lock.wait_lock, trx); ut_a(blocking_lock); print_title(i, \"TRANSACTION\"); print(trx, 3000); print_title(i, \"HOLDS THE LOCK(S)\"); print(blocking_lock); print_title(i, \"WAITING FOR THIS LOCK TO BE GRANTED\"); print(trx-&gt;lock.wait_lock); } const auto victim_it = std::find(trxs_on_cycle.begin(), trxs_on_cycle.end(), victim_trx); ut_ad(victim_it != trxs_on_cycle.end()); const auto victim_pos = std::distance(trxs_on_cycle.begin(), victim_it); ut::ostringstream buff; buff &lt;&lt; \"*** WE ROLL BACK TRANSACTION (\" &lt;&lt; (victim_pos + 1) &lt;&lt; \")\\n\"; print(buff.str().c_str()); DBUG_PRINT(\"ib_lock\", (\"deadlock detected\")); ... lock_deadlock_found = true; } - From the code analysis, it's clear that deadlocks lead to a substantial amount of log output. The ignored errors observed during testing are connected to these deadlocks. The CATS algorithm helps reduce the number of ignored errors, resulting in fewer log outputs. This problem can be consistently reproduced. Given this context, several considerations emerge: 1. Impact on Performance Testing: The extensive error logs and the resulting disruptions could potentially skew the performance evaluation, leading to inaccurate assessments of the system's capabilities. 2. Effectiveness of the CATS Algorithm: The performance improvement of the CATS algorithm may need re-evaluation. If the extensive output of error logs significantly impacts performance, its actual effectiveness may not be as high as initially believed. Remove all logs from the Deadlock_notifier::notify function, recompile MySQL, and perform SysBench read-write tests under Pareto distribution. Details are provided in the following figure: Figure 8. Impact of CATS on throughput at various concurrency levels for improved MySQL 8.0.27 after eliminating interference. From the figure, it is evident that there has been a significant change in throughput comparison. In scenarios with severe conflicts, the CATS algorithm slightly outperforms the FIFO algorithm, but the difference is minimal and much less pronounced than in previous tests. Note that these tests were conducted on the improved MySQL 8.0.27. Let's conduct performance comparison tests on the improved MySQL 8.0.32, with deadlock log interference removed, using Pareto distribution. Figure 9. Impact of CATS on throughput at various concurrency levels for improved MySQL 8.0.32 after eliminating interference. From the figure, it is evident that removing the interference results in only a slight performance difference. This small variation makes it understandable why the severity of FIFO scheduling problems may be difficult to notice. The perceived bias from CATS authors and MySQL officials likely stems from the extensive log output interference caused by deadlocks. Using the same 32 warehouses as in the CATS algorithm paper, TPC-C tests were conducted at various concurrency levels. MySQL was based on the improved MySQL 8.0.27, and BenchmarkSQL was modified to support 100 concurrent transactions per warehouse. Figure 10. Impact of CATS on throughput at different concurrency levels under NUMA after eliminating interference, according to the CATS paper. From the figure, it's evident that the CATS algorithm performs worse than the FIFO algorithm. To avoid NUMA-related interference, MySQL was bound to NUMA node 0 for a new round of throughput versus concurrency tests. Figure 11. Impact of CATS on throughput at different concurrency levels under SMP after eliminating interference, according to the CATS paper. In this round of testing, the FIFO algorithm continued to outperform the CATS algorithm. The decline in performance of the CATS algorithm in BenchmarkSQL TPC-C testing compared to improvements in SysBench Pareto testing can be attributed to the following reasons: 1. Additional Overhead: The CATS algorithm inherently introduces some extra overhead. 2. NUMA Environment Problems: The CATS algorithm may not perform optimally in NUMA environments. 3. Conflict Severity: The conflict severity in TPC-C testing is less pronounced than in SysBench Pareto testing. 4. Different Concurrency Scenarios: SysBench creates concurrency scenarios that differ significantly from those in BenchmarkSQL. Finally, standard TPC-C testing was performed again with 1000 warehouses at varying concurrency levels. Specific details are shown in the following figure: Figure 12. Impact of CATS on BenchmarkSQL throughput after eliminating interference. From the figure, it is evident that there is little difference between the two algorithms in low-conflict scenarios. In other words, the CATS algorithm does not offer significant benefits in situations with fewer conflicts. Conclusion Overall, while CATS shows some improvement in Pareto testing, it is less pronounced than expected. The interference from deadlock log outputs during performance testing impacted the results. The CATS algorithm significantly reduces transaction deadlocks, leading to fewer log outputs and less performance degradation compared to the FIFO algorithm. When deadlock logs are suppressed, the difference between these algorithms is minimal, clarifying the confusion surrounding the CATS algorithm's performance [4]. Database performance testing is inherently complex and error-prone [5]. It cannot be judged by data alone and requires thorough investigation to ensure logical consistency. References [1] B. Tian, J. Huang, B. Mozafari, and G. Schoenebeck. Contention-aware lock scheduling for transactional databases. PVLDB, 11(5), 2018. [2] Y. Wang, M. Yu, Y. Hui, F. Zhou, Y. Huang, R. Zhu, et al.. 2022. A study of database performance sensitivity to experiment settings, Proceedings of the VLDB Endowment, vol. 15, no. 7. [3] Sunny Bains. 2017. Contention-Aware Transaction Scheduling Arriving in InnoDB to Boost Performance. https://dev.mysql.com/blog-archive/. [4] Bin Wang (2024). The Art of Problem-Solving in Software Engineering: How to Make MySQL Better. [5] M. Raasveldt, P. Holanda, T. Gubner, and H. Muhleisen. Fair Benchmarking Considered Difficult: Common Pitfalls In Database Performance Testing. In 7th International Workshop on Testing Database Systems, DBTest, 2:1--2:6, 2018.",
"mainEntityOfPage": {
"@type": "WebPage",
"@id": "https://dzone.com/articles/mysql-cats-vs-fifo-performance"
},
"image": {
"@type": "ImageObject",
"url": "https://dz2cdn1.dzone.com/storage/article-thumb/18328221-thumb.jpg"
}
}
</script>
<script type="application/ld+json">
{
"@context": "https://schema.org",
"@type": "BreadcrumbList",
"itemListElement": [
{
"@type": "ListItem",
"position": 1,
"name": "DZone",
"item": "https://dzone.com"
},
{
"@type": "ListItem",
"position": 2,
"name": "Data Engineering",
"item": "https://dzone.com/data-engineering"
},
{
"@type": "ListItem",
"position": 3,
"name": "Databases",
"item": "https://dzone.com/databases"
},
{
"@type": "ListItem",
"position": 4,
"name": "Evaluating Performance Gains in MySQL Lock Scheduling Algorithms",
"item": "https://dzone.com/articles/mysql-cats-vs-fifo-performance"
}
]
}
</script>
<article>
<div class="content">
<div class="header">
<ol class="breadcrumb">
<li class="server"><a href="https://dzone.com">DZone</a></li>
<li class="server"><a href="https://dzone.com/data-engineering">Data Engineering</a></li>
<li class="server"><a href="https://dzone.com/databases">Databases</a></li>
<li class="active server">Evaluating Performance Gains in MySQL Lock Scheduling Algorithms</li>
</ol>
<div class="header-title">
<div class="title">
<h1 class="article-title">Evaluating Performance Gains in MySQL Lock Scheduling Algorithms</h1>
</div>
<div class="subhead">
<p>This article shows that MySQL’s CATS algorithm offers only a small performance gain over FIFO once deadlock logging interference is removed.</p>
</div>
<div class="publish-meta">
By<span style="user-select: none;">&nbsp;</span>
<div class="article-author-meta">
<img src="https://secure.gravatar.com/avatar/44bbe0682127fc2cfb1320c6bc6183e5?d=identicon&r=PG" class="avatar" alt="Bin Wang user avatar" width="40">
<div class="author-info">
<span class="author-name">
<a href="/users/5200737/wangbin579.html" rel="nofollow" data-core-user="false">Bin Wang</a>
</span>
</div>
&middot;
</div>
<span class="author-date">
Apr. 08, 25
</span>
&middot;
<span>Analysis</span>
</div>
</div>
</div>
<div class="author-n-useraction">
<div class="like action" x-data="engagementModal(articleId)">
<span id="activity-like-icon" class="dz-like icon-thumbs-up" x-on:click="updateStore()"></span>
<span class="action-label like-text" x-on:click="open()" x-cloak>
<span>Likes</span>
<span id="activity-like-counter" class="like-count">(1)</span>
</span>
<template x-teleport="body">
<div class="engagement-overlay" x-show="$store.article.engagement.open && nodeId === $store.article.id" x-on:keyup.escape.window="close()">
<div class="engagement-modal">
<div class="inner" x-on:click.outside="close()">
<div class="header">
<div class="title">Likes</div>
<button class="close" x-on:click="close()"></button>
</div>
<div class="content">
<div x-show="$store.article.engagement.initializing" class="loading-screen">
<i class="icon icon-spin3 anim-spin"></i>
</div>
<div x-show="!$store.article.engagement.initializing">
<template x-for="user in $store.article.engagement.users" :key="user.id">
<div class="media">
<div class="media-left">
<img class="avatar"
x-bind:src="user.profile.profileImage"
loading="lazy"
width="50"
height="50"
>
</div>
<div class="media-right">
<a x-bind:href="user.computed.url" x-html="user.profile.name"></a>
<div x-show="formatJobData(user)" x-html="formatJobData(user)"></div>
</div>
</div>
</template>
</div>
<div x-show="isDataUnavailable()" class="center-screen">
<div x-show="!$store.article.engagement.unauthorized">
<div>There are no likes...yet! &#128064;</div>
<div>Be the first to like this post!</div>
</div>
<div x-show="$store.article.engagement.unauthorized">
<div>It looks like you're not logged in.</div>
<div><a href="/users/login.html">Sign in</a> to see who liked this post!</div>
</div>
</div>
<div x-show="isFooterShowing()">
<div class="footer">
<button class="btn btn-primary" x-on:click="fetchEngagements()"
x-bind:disabled="$store.article.engagement.loading"
>
Load More
<i x-show="$store.article.engagement.loading" class="icon icon-spin3 anim-spin"></i>
</button>
</div>
</div>
</div>
</div>
</div>
</div>
</template> </div>
<div class="action comment-action">
<span class="comment">
<i class="icon-comment"></i>
<span class="action-label">Comment</span>
<span id="activity-comment-counter" class="comment-count"></span>
</span>
</div>
<div class="save action">
<div id="activity-save-icon" class="save icon-star-empty">
<span id="activity-save-text" class="action-label">Save</span>
</div>
</div>
<div class="tweet action">
<a id="tweet-link" href="" class="title" target="_blank">
<span><i class="icon-twitter"></i></span>
<span class="action-label">Tweet</span>
</a>
</div>
<div class="linkedin action">
<a id="linkedin-link" href="https://www.linkedin.com/sharing/share-offsite/?url=https://dzone.com/articles/mysql-cats-vs-fifo-performance" class="title" target="_blank">
<span><i class="icon-linkedin-1"></i></span>
<span class="action-label">Share</span>
</a>
</div>
<div class="right-most">
<div id="activity-view-container" class="article-views action">
<i class="icon-eye"></i>
<span class="action-label view-count">5.4K Views</span>
</div>
</div>
</div>
<div class="signin-prompt">
<p>Join the DZone community and get the full member experience.</p>
<a id="article-signin-prompt" href="/static/registration.html">Join For Free</a>
</div>
<div class="arrow-down"></div>
<div id="top-bumper-container"></div>
<div>
<div class="content-html"><p>Scheduling is crucial in computer system design. The right policy can significantly reduce mean response time without needing faster machines, effectively improving performance for free. Scheduling also optimizes other metrics, such as user fairness and differentiated service levels, ensuring some job classes have lower mean delays than others [1].</p>
<p>MySQL 8.0 uses the Contention-Aware Transaction Scheduling (CATS) algorithm to prioritize transactions waiting for locks. When multiple transactions compete for the same lock, CATS determines the priority based on scheduling weight, calculated by the number of transactions a given transaction blocks. The transaction blocking the most others gets higher priority; if weights are equal, the longest waiting transaction goes first.</p>
<p>A deadlock occurs when multiple transactions cannot proceed because each holds a lock needed by another, causing all involved to wait indefinitely without releasing their locks.</p>
<h2>Comparing CATS and FIFO Performance</h2>
<p>After understanding the MySQL lock scheduling algorithm, let's examine how this algorithm affects throughput. Before testing, it is necessary to understand the previous FIFO algorithm and how to restore it. For relevant details, refer to the git log explanations provided below.</p>
<p><em>This WL improves the implementation of CATS to the point where the FCFS will be redundant (as often slower, and easy to "emulate" by setting equal schedule weights in CATS), so it removes FCFS from the code, further simplifying the lock_sys's logic.</em></p>
<p>Based on the above prompt, restoring the FIFO lock scheduling algorithm in MySQL is straightforward. Subsequently, throughput was tested using SysBench Pareto distribution scenarios with varying concurrency levels in the improved MySQL 8.0.32. Details are provided in the following figure.</p>
<p><img style="width: 808px;" class="fr-fic fr-dib lazyload" data-image="true" data-new="false" data-sizeformatted="26.2 kB" data-mimetype="image/png" data-creationdate="1726121988095" data-creationdateformatted="09/12/2024 06:19 AM" data-type="temp" data-url="https://dz2cdn1.dzone.com/storage/temp/17915078-1726121986281.png" data-modificationdate="null" data-size="26196" data-name="1726121986281.png" data-id="17915078" data-src="https://dz2cdn1.dzone.com/storage/temp/17915078-1726121986281.png" alt="Figure 1. Impact of CATS on throughput at various concurrency levels."></p>
<p style="text-align: center;"><em>Figure 1. Impact of CATS on throughput at various concurrency levels.</em></p>
<p>From the figure, it can be seen that the throughput of the CATS algorithm significantly exceeds that of the FIFO algorithm. To compare these two algorithms in terms of user response time, refer to the following figure.</p>
<p><s><img style="width: 808px;" class="fr-fic fr-dib lazyload" data-image="true" data-new="false" data-sizeformatted="25.8 kB" data-mimetype="image/png" data-creationdate="1726122033865" data-creationdateformatted="09/12/2024 06:20 AM" data-type="temp" data-url="https://dz2cdn1.dzone.com/storage/temp/17915081-1726122032954.png" data-modificationdate="null" data-size="25781" data-name="1726122032954.png" data-id="17915081" data-src="https://dz2cdn1.dzone.com/storage/temp/17915081-1726122032954.png" alt="Impact of CATS on response time at various concurrency levels."></s></p>
<p style="text-align: center;"><em>Figure 2. Impact of CATS on response time at various concurrency levels.</em></p>
<p>From the figure, it can be seen that the CATS algorithm provides significantly better user response times.</p>
<p>Furthermore, comparing deadlock error statistics during the Pareto distribution test process, details can be found in the following figure.</p>
<p><img style="width: 801px;" class="fr-fic fr-dib lazyload" data-image="true" data-new="false" data-sizeformatted="24.1 kB" data-mimetype="image/png" data-creationdate="1726122072059" data-creationdateformatted="09/12/2024 06:21 AM" data-type="temp" data-url="https://dz2cdn1.dzone.com/storage/temp/17915083-1726122071187.png" data-modificationdate="null" data-size="24090" data-name="1726122071187.png" data-id="17915083" data-src="https://dz2cdn1.dzone.com/storage/temp/17915083-1726122071187.png" alt="Impact of CATS on ignored errors at various concurrency levels."></p>
<p style="text-align: center;"><em>Figure 3. Impact of CATS on ignored errors at various concurrency levels.</em></p>
<p>Comparative analysis shows that the CATS algorithm significantly reduces deadlocks. This reduction in deadlocks likely plays a key role in improving performance. The theoretical basis for this correlation is as follows [2]:</p>
<p><em>Under a high-contention setting, the throughput of the target system will be determined by the concurrency control mechanism of the target system: systems which can release locks earlier or reduce the number of aborts will have advantages in such a setting.</em></p>
<p>The above test results align closely with MySQL's official findings. The following two figures, based on official tests [3], demonstrate the significant effectiveness of the CATS algorithm.</p>
<p><img style="width: 808px;" class="fr-fic fr-dib lazyload" data-image="true" data-new="false" data-sizeformatted="239.6 kB" data-mimetype="image/png" data-creationdate="1726122607004" data-creationdateformatted="09/12/2024 06:30 AM" data-type="temp" data-url="https://dz2cdn1.dzone.com/storage/temp/17915089-1726122604745.png" data-modificationdate="null" data-size="239565" data-name="1726122604745.png" data-id="17915089" data-src="https://dz2cdn1.dzone.com/storage/temp/17915089-1726122604745.png" alt="Comparison of CATS and FIFO in TPS and mean latency: insights from the MySQL blog."></p>
<p style="text-align: center;"><em>Figure 4. Comparison of CATS and FIFO in TPS and mean latency: insights from the MySQL blog.</em></p>
<p>Additionally, MySQL's official requirements for implementing the CATS algorithm are stringent. Specific details are provided in the following figure:</p>
<p><img style="width: 788px;" class="fr-fic fr-dib lazyload" data-image="true" data-new="false" data-sizeformatted="112.5 kB" data-mimetype="image/png" data-creationdate="1726122438449" data-creationdateformatted="09/12/2024 06:27 AM" data-type="temp" data-url="https://dz2cdn1.dzone.com/storage/temp/17915087-1726122437512.png" data-modificationdate="null" data-size="112455" data-name="1726122437512.png" data-id="17915087" data-src="https://dz2cdn1.dzone.com/storage/temp/17915087-1726122437512.png" alt="Requirements of the official worklog for CATS."></p>
<p style="text-align: center;"><em>Figure 5. Requirements of the official worklog for CATS.</em></p>
<p>Therefore, with the adoption of the CATS algorithm, performance degradation should be absent in all scenarios. It seems like things end here, but the summary in the CATS algorithm's paper [1] raises some doubts. Details are provided in the following figure:</p>
<p><img style="width: 808px;" class="fr-fic fr-dib lazyload" data-image="true" data-new="false" data-sizeformatted="151.7 kB" data-mimetype="image/png" data-creationdate="1726122636880" data-creationdateformatted="09/12/2024 06:30 AM" data-type="temp" data-url="https://dz2cdn1.dzone.com/storage/temp/17915092-1726122636010.png" data-modificationdate="null" data-size="151747" data-name="1726122636010.png" data-id="17915092" data-src="https://dz2cdn1.dzone.com/storage/temp/17915092-1726122636010.png" alt="Doubts about the CATS paper."></p>
<p style="text-align: center;"><em>Figure 6. Doubts about the CATS paper.</em></p>
<p>From the information above, it can be inferred that either the industry has overlooked potential flaws in FIFO, or the paper's assessment is flawed, and FIFO does not have the serious problems suggested. This contradiction highlights a critical problem: one of these conclusions must be flawed; both cannot be correct.</p>
<p>Contradictions often present valuable opportunities for in-depth problem analysis and resolution. They highlight areas where existing understanding may be challenged or where new insights can be gained.</p>
<p>This time, testing on the improved MySQL 8.0.27 revealed significant bottlenecks under severe conflicts. The <em>perf&nbsp;</em>screenshot is shown in the following figure:</p>
<p>This time, testing on the improved MySQL 8.0.27 revealed a large number of error logs in the MySQL error log file. Below is a partial screenshot:&nbsp;</p>
<p><img style="width: 808px;" class="fr-fic fr-dib lazyload" data-image="true" data-new="false" data-sizeformatted="170.3 kB" data-mimetype="image/png" data-creationdate="1726122720549" data-creationdateformatted="09/12/2024 06:32 AM" data-type="temp" data-url="https://dz2cdn1.dzone.com/storage/temp/17915094-1726122719636.png" data-modificationdate="null" data-size="170299" data-name="1726122719636.png" data-id="17915094" data-src="https://dz2cdn1.dzone.com/storage/temp/17915094-1726122719636.png" alt="Partial screenshot of numerous error logs."></p>
<p style="text-align: center;"><em>Figure 7. Partial screenshot of numerous error logs.</em></p>
<p>Continuing the analysis of the corresponding code, the specifics are as follows:</p>
<div class="codeMirror-wrapper newest" contenteditable="false">
<div contenteditable="false">
<div class="codeHeader">
<div class="nameLanguage">
C++
</div><i class="icon-cancel-circled-1 cm-remove">&nbsp;</i>
</div>
<div class="codeMirror-code--wrapper" data-code="void Deadlock_notifier::notify(const ut::vector<const trx_t *> &amp;trxs_on_cycle,
const trx_t *victim_trx) {
ut_ad(locksys::owns_exclusive_global_latch());
start_print();
const auto n = trxs_on_cycle.size();
for (size_t i = 0; i < n; ++i) {
const trx_t *trx = trxs_on_cycle[i];
const trx_t *blocked_trx = trxs_on_cycle[0 < i ? i - 1 : n - 1];
const lock_t *blocking_lock =
lock_has_to_wait_in_queue(blocked_trx->lock.wait_lock, trx);
ut_a(blocking_lock);
print_title(i, &quot;TRANSACTION&quot;);
print(trx, 3000);
print_title(i, &quot;HOLDS THE LOCK(S)&quot;);
print(blocking_lock);
print_title(i, &quot;WAITING FOR THIS LOCK TO BE GRANTED&quot;);
print(trx->lock.wait_lock);
}
const auto victim_it =
std::find(trxs_on_cycle.begin(), trxs_on_cycle.end(), victim_trx);
ut_ad(victim_it != trxs_on_cycle.end());
const auto victim_pos = std::distance(trxs_on_cycle.begin(), victim_it);
ut::ostringstream buff;
buff << &quot;*** WE ROLL BACK TRANSACTION (&quot; << (victim_pos + 1) << &quot;)\n&quot;;
print(buff.str().c_str());
DBUG_PRINT(&quot;ib_lock&quot;, (&quot;deadlock detected&quot;));
...
lock_deadlock_found = true;
}
-" data-lang="text/x-c++src">
<pre><code lang="text/x-c++src">void Deadlock_notifier::notify(const ut::vector&lt;const trx_t *&gt; &amp;trxs_on_cycle,
const trx_t *victim_trx) {
ut_ad(locksys::owns_exclusive_global_latch());
start_print();
const auto n = trxs_on_cycle.size();
for (size_t i = 0; i &lt; n; ++i) {
const trx_t *trx = trxs_on_cycle[i];
const trx_t *blocked_trx = trxs_on_cycle[0 &lt; i ? i - 1 : n - 1];
const lock_t *blocking_lock =
lock_has_to_wait_in_queue(blocked_trx-&gt;lock.wait_lock, trx);
ut_a(blocking_lock);
print_title(i, "TRANSACTION");
print(trx, 3000);
print_title(i, "HOLDS THE LOCK(S)");
print(blocking_lock);
print_title(i, "WAITING FOR THIS LOCK TO BE GRANTED");
print(trx-&gt;lock.wait_lock);
}
const auto victim_it =
std::find(trxs_on_cycle.begin(), trxs_on_cycle.end(), victim_trx);
ut_ad(victim_it != trxs_on_cycle.end());
const auto victim_pos = std::distance(trxs_on_cycle.begin(), victim_it);
ut::ostringstream buff;
buff &lt;&lt; "*** WE ROLL BACK TRANSACTION (" &lt;&lt; (victim_pos + 1) &lt;&lt; ")\n";
print(buff.str().c_str());
DBUG_PRINT("ib_lock", ("deadlock detected"));
...
lock_deadlock_found = true;
}
-</code></pre>
</div>
</div>
</div>
<p><br></p>
<p>From the code analysis, it's clear that deadlocks lead to a substantial amount of log output. The ignored errors observed during testing are connected to these deadlocks. The CATS algorithm helps reduce the number of ignored errors, resulting in fewer log outputs. This problem can be consistently reproduced.</p>
<p>Given this context, several considerations emerge:</p>
<p>1. &nbsp;<strong>Impact on Performance Testing:</strong> The extensive error logs and the resulting disruptions could potentially skew the performance evaluation, leading to inaccurate assessments of the system's capabilities.</p>
<p>2. &nbsp;<strong>Effectiveness of the CATS Algorithm:</strong> The performance improvement of the CATS algorithm may need re-evaluation. If the extensive output of error logs significantly impacts performance, its actual effectiveness may not be as high as initially believed.</p>
<p>Remove all logs from the <strong>Deadlock_notifier::notify</strong> function, recompile MySQL, and perform SysBench read-write tests under Pareto distribution. Details are provided in the following figure:</p>
<p><img style="width: 808px;" class="fr-fic fr-dib lazyload" data-image="true" data-new="false" data-sizeformatted="23.1 kB" data-mimetype="image/png" data-creationdate="1726122909993" data-creationdateformatted="09/12/2024 06:35 AM" data-type="temp" data-url="https://dz2cdn1.dzone.com/storage/temp/17915095-1726122908284.png" data-modificationdate="null" data-size="23145" data-name="1726122908284.png" data-id="17915095" data-src="https://dz2cdn1.dzone.com/storage/temp/17915095-1726122908284.png"></p>
<p style="text-align: center;"><em>Figure 8. Impact of CATS on throughput at various concurrency levels for improved MySQL 8.0.27 after eliminating interference.</em></p>
<p>From the figure, it is evident that there has been a significant change in throughput comparison. In scenarios with severe conflicts, the CATS algorithm slightly outperforms the FIFO algorithm, but the difference is minimal and much less pronounced than in previous tests. Note that these tests were conducted on the improved MySQL 8.0.27.</p>
<p>Let's conduct performance comparison tests on the improved MySQL 8.0.32, with deadlock log interference removed, using Pareto distribution.</p>
<p><img style="width: 808px;" class="fr-fic fr-dib lazyload" data-image="true" data-new="false" data-sizeformatted="24.1 kB" data-mimetype="image/png" data-creationdate="1726122934319" data-creationdateformatted="09/12/2024 06:35 AM" data-type="temp" data-url="https://dz2cdn1.dzone.com/storage/temp/17915096-1726122933439.png" data-modificationdate="null" data-size="24067" data-name="1726122933439.png" data-id="17915096" data-src="https://dz2cdn1.dzone.com/storage/temp/17915096-1726122933439.png"></p>
<p style="text-align: center;"><em>Figure 9. Impact of CATS on throughput at various concurrency levels for improved MySQL 8.0.32 after eliminating interference.</em></p>
<p>From the figure, it is evident that removing the interference results in only a slight performance difference. This small variation makes it understandable why the severity of FIFO scheduling problems may be difficult to notice. The perceived bias from CATS authors and MySQL officials likely stems from the extensive log output interference caused by deadlocks.</p>
<p>Using the same 32 warehouses as in the CATS algorithm paper, TPC-C tests were conducted at various concurrency levels. MySQL was based on the improved MySQL 8.0.27, and BenchmarkSQL was modified to support 100 concurrent transactions per warehouse.</p>
<p><img style="width: 795px;" class="fr-fic fr-dib lazyload" data-image="true" data-new="false" data-sizeformatted="36.2 kB" data-mimetype="image/png" data-creationdate="1726122985349" data-creationdateformatted="09/12/2024 06:36 AM" data-type="temp" data-url="https://dz2cdn1.dzone.com/storage/temp/17915097-1726122984444.png" data-modificationdate="null" data-size="36206" data-name="1726122984444.png" data-id="17915097" data-src="https://dz2cdn1.dzone.com/storage/temp/17915097-1726122984444.png"></p>
<p style="text-align: center;"><em>Figure 10. Impact of CATS on throughput at different concurrency levels under NUMA after eliminating interference, according to the CATS paper.</em></p>
<p>From the figure, it's evident that the CATS algorithm performs worse than the FIFO algorithm. To avoid NUMA-related interference, MySQL was bound to NUMA node 0 for a new round of throughput versus concurrency tests.</p>
<p><img style="width: 808px;" class="fr-fic fr-dib lazyload" data-image="true" data-new="false" data-sizeformatted="32.4 kB" data-mimetype="image/png" data-creationdate="1726123021501" data-creationdateformatted="09/12/2024 06:37 AM" data-type="temp" data-url="https://dz2cdn1.dzone.com/storage/temp/17915098-1726123020535.png" data-modificationdate="null" data-size="32445" data-name="1726123020535.png" data-id="17915098" data-src="https://dz2cdn1.dzone.com/storage/temp/17915098-1726123020535.png"></p>
<p style="text-align: center;"><em>Figure 11. Impact of CATS on throughput at different concurrency levels under SMP after eliminating interference, according to the CATS paper.</em></p>
<p>In this round of testing, the FIFO algorithm continued to outperform the CATS algorithm. The decline in performance of the CATS algorithm in BenchmarkSQL TPC-C testing compared to improvements in SysBench Pareto testing can be attributed to the following reasons:</p>
<p>1. &nbsp;<strong>Additional Overhead:</strong> The CATS algorithm inherently introduces some extra overhead.</p>
<p>2. &nbsp;<strong>NUMA Environment Problems:</strong> The CATS algorithm may not perform optimally in NUMA environments.</p>
<p>3. &nbsp;<strong>Conflict Severity:&nbsp;</strong>The conflict severity in TPC-C testing is less pronounced than in SysBench Pareto testing.</p>
<p>4. &nbsp;<strong>Different Concurrency Scenarios:&nbsp;</strong>SysBench creates concurrency scenarios that differ significantly from those in BenchmarkSQL.</p>
<p>Finally, standard TPC-C testing was performed again with 1000 warehouses at varying concurrency levels. Specific details are shown in the following figure:</p>
<p><img style="width: 808px;" class="fr-fic fr-dib lazyload" data-image="true" data-new="false" data-sizeformatted="26.8 kB" data-mimetype="image/png" data-creationdate="1726123057292" data-creationdateformatted="09/12/2024 06:37 AM" data-type="temp" data-url="https://dz2cdn1.dzone.com/storage/temp/17915099-1726123056370.png" data-modificationdate="null" data-size="26774" data-name="1726123056370.png" data-id="17915099" data-src="https://dz2cdn1.dzone.com/storage/temp/17915099-1726123056370.png"></p>
<p style="text-align: center;"><em>Figure 12. Impact of CATS on BenchmarkSQL throughput after eliminating interference.</em></p>
<p>From the figure, it is evident that there is little difference between the two algorithms in low-conflict scenarios. In other words, the CATS algorithm does not offer significant benefits in situations with fewer conflicts.</p>
<h2>Conclusion</h2>
<p>Overall, while CATS shows some improvement in Pareto testing, it is less pronounced than expected. The interference from deadlock log outputs during performance testing impacted the results. The CATS algorithm significantly reduces transaction deadlocks, leading to fewer log outputs and less performance degradation compared to the FIFO algorithm. When deadlock logs are suppressed, the difference between these algorithms is minimal, clarifying the confusion surrounding the CATS algorithm's performance [4].</p>
<p>Database performance testing is inherently complex and error-prone [5]. It cannot be judged by data alone and requires thorough investigation to ensure logical consistency.</p>
<h2><strong>References</strong></h2>
<p>[1] B. Tian, J. Huang, B. Mozafari, and G. Schoenebeck. Contention-aware lock scheduling for transactional databases. PVLDB, 11(5), 2018.</p>
<p>[2] Y. Wang, M. Yu, Y. Hui, F. Zhou, Y. Huang, R. Zhu, et al.. 2022. A study of database performance sensitivity to experiment settings, Proceedings of the VLDB Endowment, vol. 15, no. 7.</p>
<p>[3] Sunny Bains. 2017. Contention-Aware Transaction Scheduling Arriving in InnoDB to Boost Performance. https://dev.mysql.com/blog-archive/.</p>
<p>[4] Bin Wang (2024). The Art of Problem-Solving in Software Engineering: How to Make MySQL Better.</p>
<p>[5] M. Raasveldt, P. Holanda, T. Gubner, and H. Muhleisen. Fair Benchmarking Considered Difficult: Common Pitfalls In Database Performance Testing. In 7th International Workshop on Testing Database Systems, DBTest, 2:1--2:6, 2018.</p></div>
</div>
<div id="bottom-bumper-container"></div>
<div class="article-tag-pill-container">
<span class="article-tag-pill">MySQL</span>
<span class="article-tag-pill">CATS (software)</span>
<span class="article-tag-pill">Performance</span>
</div>
<div class="attribution">
<p>Opinions expressed by DZone contributors are their own.</p>
</div>
</div>
</article>
</div>
<div class="trending-separator goto"></div>
<aside class="trending goto" aria-labelledby="related-mobile-heading">
<h2 id="related-mobile-heading">Related</h2>
<ul>
<li class="item">
<a href="/articles/master-sql-performance-optimization-techniques" class="goto-link related-link">Master SQL Performance Optimization: Step-by-Step Techniques With Case Studies</a>
</li>
<li class="item">
<a href="/articles/mysql-80-performance-degradation-analysis" class="goto-link related-link">In-Depth Analysis of MySQL 8.0 Performance Degradation</a>
</li>
<li class="item">
<a href="/articles/fine-tuning-mysql-performance-resolving-issues" class="goto-link related-link">Fine-Tuning Performance, Resolving Common Issues in FinTech Application With MySQL</a>
</li>
<li class="item">
<a href="/articles/databricks-cache-improves-analytics-workloads" class="goto-link related-link">Improving Repeated Analytics Workloads With Databricks Disk Cache</a>
</li>
</ul>
</aside>
</div>
<div id="div-gpt-ad-1435246566686-11" class="ads-bottom-leaderboard dz2_article_bottom" data-gpt-slot="bottom"></div>
<div class="layout-card widget-top-border partner-resources-block" style="width:100%; margin-bottom: 1em;">
<div class="main-container">
<div class="featured-header">
<h2>
<span>Partner Resources</span>
</h2>
</div>
<div class="partner-resources-container">
<div id="div-gpt-ad-1435246566686-5" class="resource-block dz2_partner_resource_link" data-gpt-slot="partner" data-gpt-position="pr1"></div>
<div id="div-gpt-ad-1435246566686-6" class="resource-block dz2_partner_resource_link" data-gpt-slot="partner" data-gpt-position="pr2"></div>
<div id="div-gpt-ad-1435246566686-7" class="resource-block dz2_partner_resource_link" data-gpt-slot="partner" data-gpt-position="pr3"></div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
<div class="bottom-sticky-ad-container">
<span class="bottom-sticky-ad-close" title="close"
x-on:click="$el.parentElement.classList.add('closed')">×</span>
<div id="div-gpt-ad-1635294790718-12" class="bottom-sticky-ad dz2_sticky_footer_leaderboard" data-gpt-slot="bottomStickyFooter"></div>
</div>
<div class="modal fade bd-example-modal-lg" id="modal-message" tabindex="-1" role="dialog" aria-hidden="true">
<div class="modal-dialog">
<div class="modal-content">
<div class="modal-header"></div>
<div class="modal-body"></div>
</div>
</div>
</div>
</div>
</div>
<div class="comments-overlay"></div>
<div id="comment-box">
<div class="comment-box-wrapper">
<div id="comment-input-editor"></div>
</div>
<div class="info hidden"></div>
<div class="comments-content" style="display: none;">
<div class="comment-header">
<hr />
<span class="icon-comment">
<span class="numOfComments"></span> Comments
</span>
</div>
<div class="comments"></div>
</div>
</div>
<script async>var articleTitle = 'Evaluating Performance Gains in MySQL Lock Scheduling Algorithms';
var articleUrl = 'https://dzone.com/articles/mysql-cats-vs-fifo-performance';
var retweetLink = document.querySelector('#tweet-link');
function retweet(event) {
event.preventDefault();
event.stopPropagation();
var twitter = 'https://twitter.com/intent/tweet';
var params = '?text=' + encodeURIComponent(articleTitle) + '&url=' + articleUrl + '&ref=dzone.com&via=DZoneInc';
var win = window.open(twitter + params, '_blank');
win.focus();
}
retweetLink.addEventListener('click', retweet);
function showStatusMessage(options) {
var modal = document.getElementById('modal-message');
if(modal) {
modal.classList.add(options.type);
var modalBody = modal.querySelector('.modal-content .modal-body');
var modalHeader = modal.querySelector('.modal-content .modal-header');
modalHeader.innerText = options.header ? options.header : '';
modalBody.innerText = options.body ? options.body : '';
$(modal).modal('show');
$(modal).on('hidden.bs.modal', function () {
modal.classList.remove(options.type);
});
}
}
function showConfirmMessage(options) {
var modal = document.getElementById('modal-message');
if(modal) {
modal.classList.add(options.type);
var modalBody = modal.querySelector('.modal-content .modal-body');
var modalHeader = modal.querySelector('.modal-content .modal-header');
modalHeader.innerText = options.header ? options.header : '';
modalBody.innerText = options.body ? options.body : '';
if (options.textarea) {
var textareaDiv = document.createElement('div');
var textareaLabel = document.createElement('label');
textareaLabel.setAttribute('for', 'modal-textarea');
textareaLabel.innerText = options.textarea.label;
var textarea = document.createElement('textarea');
textarea.id = 'modal-textarea';
textarea.placeholder = (options.textarea.placeholder || '');
textarea.setAttribute('rows', (options.textarea.rows || 3));
textarea.classList.add('form-control', 'not-resizable');
if (options.textarea.maxlength) {
textarea.maxLength = options.textarea.maxlength;
}
textareaDiv.appendChild(textareaLabel);
textareaDiv.appendChild(textarea);
modalBody.appendChild(textareaDiv);
}
var btnContainer = document.createElement('div');
btnContainer.classList.add('btn-container');
var noBtn = document.createElement('button');
noBtn.innerText = options.noBtnText ? options.noBtnText : 'No';
noBtn.classList.add('no-btn');
var yesBtn = document.createElement('button');
yesBtn.innerText = options.yesBtnText ? options.yesBtnText : 'Yes';
yesBtn.classList.add('yes-btn');
btnContainer.appendChild(noBtn);
btnContainer.appendChild(yesBtn);
modalBody.appendChild(btnContainer);
$(modal).modal('show');
$(noBtn).one('click', function() {
$(modal).modal('hide');
if(options.noCallback) {
$(modal).one('hidden.bs.modal', function () {
options.noCallback();
});
}
});
$(yesBtn).one('click', function() {
$(modal).modal('hide');
if(options.yesCallback) {
$(modal).one('hidden.bs.modal', function () {
options.yesCallback();
});
}
});
$(modal).on('hidden.bs.modal', function () {
modal.classList.remove(options.type);
});
}
}
function getSuspensionBody() {
return 'We regret to inform you that your DZone account has been suspended for violating our Guidelines. ' +
'Please reach out to editors@dzone.com if you would like additional information.';
}</script>
<style>.engagement-overlay {
width: 100%;
height: 100%;
position: fixed;
top: 0;
left: 0;
background: rgb(0, 0, 0, 0.5);
z-index: 10000;
}
.engagement-modal {
display: flex;
align-items: center;
justify-content: center;
position: fixed;
z-index: 10;
width: 100%;
height: 100%;
}
.engagement-modal .inner {
background-color: white;
border-radius: 0.5em;
margin: auto;
border: 1px solid #cccccc;
}
.engagement-modal .header {
padding: 20px 50px 10px 30px;
position: relative;
}
.engagement-modal .title {
font-size: 20px;
font-weight: bold;
color: #333333;
}
.engagement-modal .title:hover {
text-decoration: none;
}
.engagement-modal .close {
font-size: 18px;
position: absolute;
top: 18px;
right: 20px;
width: 32px;
height: 32px;
background: none;
border: none;
opacity: 0.8;
font-weight: bold;
text-shadow: 0 1px 0 #fff;
}
.engagement-modal .close:hover {
background-color: rgba(146, 148, 151, 0.2);
color: #000;
border-radius: 50%;
}
.engagement-modal .close:after {
content: '\2715';
}
.engagement-modal .content {
padding: 0 30px 20px;
width: min(450px, 90vw);
height: min(450px, 90vw);
scrollbar-width: thin;
overflow: auto;
overscroll-behavior: contain;
}
.engagement-modal .loading-screen,
.engagement-modal .content .center-screen {
display: flex;
justify-content: center;
align-items: center;
height: 100%;
font-size: 18px;
}
.engagement-modal .content .center-screen a {
color: var(--acc-ffffff-blue-1);
font-weight: bold;
}
.engagement-modal .loading-screen i {
font-size: 24px;
}
.engagement-modal .media-left,
.engagement-modal .media-right {
display: table-cell;
vertical-align: top;
}
.engagement-modal .media-left {
padding-right: 10px;
}
.engagement-modal .media-right {
padding-left: 10px;
}
.engagement-modal .media a {
color: black;
font-size: 16px;
}
.engagement-modal .avatar {
border-radius: 50%;
}
.engagement-modal .footer {
margin: 20px 0 0;
display: flex;
justify-content: center;
align-items: center;
background-color: unset !important;
border-top: none !important;
}
.engagement-modal .footer .btn {
border: 1px solid transparent;
}
.engagement-modal .footer .btn-primary {
color: #fff;
border-color: #2e6da4;
}
.engagement-modal .footer button {
background-color: var(--acc-ffffff-blue-2);
padding: 6px 12px;
border-radius: 4px;
}
.engagement-modal .footer button:hover {
filter: brightness(1.2);
}
@keyframes anim-spin {
0% {
transform: rotate(0deg);
}
100% {
transform: rotate(359deg);
}
}
.engagement-modal .anim-spin {
display: inline-block;
animation: anim-spin 2s infinite linear;
}</style>
<script>document.addEventListener('alpine:init', () => {
Alpine.data('engagementModal', (nodeId) => ({
nodeId: null,
init() {
this.nodeId = nodeId;
},
open() {
this.updateStore();
this.$store.article.engagement.open = true;
if (this.$store.article.engagement.page === 1 && !this.$store.article.engagement.unauthorized) {
this.$store.article.engagement.initializing = true;
this.fetchEngagements();
}
},
close() {
if (this.$store.article.engagement.open) {
this.$store.article.engagement.open = false;
}
},
updateStore() {
if (this.nodeId !== this.$store.article.id) {
this.$store.article.engagement.reset();
this.$store.article.id = this.nodeId;
}
},
fetchEngagements() {
if (this.$store.article.engagement.loading || !this.$store.article.engagement.additional) {
return;
}
this.$store.article.engagement.loading = true;
this.$store.global.getFromService('/services/nodes/' + this.$store.article.id + '/engagements?page=' + this.$store.article.engagement.page)
.then(res => {
res.json().then(data => {
for (let user of data.engagements) {
this.$store.article.engagement.users.push(user);
}
this.$store.article.engagement.additional = data.additional;
this.$store.article.engagement.page++;
});
})
.catch(err => {
err.json().then(data => {
if (data.error?.code === 4011) {
this.$store.article.engagement.unauthorized = true;
} else {
this.$store.modal_engagement_error.open();
}
});
})
.finally(() => {
// Allow the loader to gracefully exit
setTimeout(() => {
this.$store.article.engagement.loading = false;
this.$store.article.engagement.initializing = false;
}, 200);
});
},
formatJobData(user) {
if (user.profile.jobTitle && user.profile.companyName) {
return user.profile.jobTitle + ', ' + user.profile.companyName;
}
if (user.profile.jobTitle) {
return user.profile.jobTitle;
}
if (user.profile.companyName) {
return user.profile.companyName;
}
return null;
},
isDataUnavailable() {
return !this.$store.article.engagement.initializing && !this.$store.article.engagement.users.length;
},
isFooterShowing() {
return !this.$store.article.engagement.initializing
&& this.$store.article.engagement.additional
&& this.$store.article.engagement.page > 1;
}
}));
});
</script>
<div class="alpine-overlay" x-cloak x-show="$store.modal_engagement_error._open">
<div id="modal_engagement_error"
class="alpine-modal"
role="dialog"
tabindex="-1"
x-show="$store.modal_engagement_error._open"
x-on:click.self="$store.modal_engagement_error.dismissible && $store.modal_engagement_error.close()"
x-cloak
x-transition
>
<div class="dz-style modal-inner centered relative">
<button x-show="$store.modal_engagement_error.closeable"
class="btn-close"
x-on:click="$store.modal_engagement_error.close()"
aria-label="Close">
</button>
<div x-show="$store.modal_engagement_error.title" class="modal-header p-sm mt-sm mb-md">
<div class="title " x-text="$store.modal_engagement_error.title"></div>
</div>
<div class="modal-content py-md px-lg" x-bind:class="{ 'has-top-border': $store.modal_engagement_error.title }">
<p x-show="$store.modal_engagement_error.bodyText" class="my-none" x-text="$store.modal_engagement_error.bodyText"></p>
<p>The likes didn't load as expected. Please refresh the page and try again.</p>
</div>
<div x-show="$store.modal_engagement_error.options.length" class="modal-footer p-sm">
<template x-for="option in $store.modal_engagement_error.options">
<button x-show="option.canDisplay" x-text="option.text"
type="button"
x-bind:id="'button_modal_engagement_error_' + option.index"
x-bind:class="option.classList"
x-on:click="option.onClick"
x-bind:disabled="option.isDisabled"
></button>
</template>
</div>
</div>
</div>
</div>
<script>
document.addEventListener("alpine:init", () => {
Alpine.store("modal_engagement_error", {
_open: false,
title: "Oops! Something Went Wrong",
bodyText: null,
options: [{"action":"dismiss","text":"Close"}],
closeable: true,
dismissible: true,
open(data) {
if (data) {
if (data.title) {
this.title = data.title;
}
if (data.bodyText) {
this.bodyText = data.bodyText;
}
if (data.options) {
this.options = data.options;
}
if (data.dismissAfterMs) {
setTimeout(() => this._open = false, data.dismissAfterMs);
}
}
this.updateOptions();
this._open = true;
},
close() {
// Manually click the buttons in which should run on dismiss.
// This is to keep the context. Calling this[option.action]() will not work.
for (let option of this.options) {
if (option.runOnDismiss) {
const element = document.querySelector('#button_modal_engagement_error_' + option.index);
element.click();
}
}
this._open = false;
},
updateOptions() {
const btnStyle = this.options.length === 2 ? ' btn-default' : '';
this.options = this.options.map((o, idx) => ({
...o,
index: idx,
classList: o.classList ? o.classList : (idx === 0 ? "btn btn-primary hov-brighten" : "btn hov-underline" + btnStyle),
onClick: function() {
if (o.action !== "dismiss") {
this[o.action]();
}
this.$store["modal_engagement_error"].close();
},
isDisabled: function() {
return Object.hasOwn(o, 'disabled') && this[o.disabled]();
},
canDisplay: function() {
return !Object.hasOwn(o, 'condition') || this[o.condition]();
}
}));
},
init() {
this.updateOptions();
}
});
});
</script>
<link rel="stylesheet" media="all" href="https://dz2cdn1.dzone.com/themes/dz20/ftl/footer/styles.css">
<div id="ftl-footer">
<div class="container-fluid footerOuter" style="padding-bottom: 90px;">
<div class="row">
<div class="col-md-12">
<div class="container">
<div class="row footer">
<div class="col-md-12 footerWidget">
<div class="row footerContainer footer">
<div class="left col-xs-12 col-sm-7">
<div class="col-xs-12 social-media-icons footer-mobile">
<ul class="icons-only">
<li class="rss-icon" id="rss-footer-1">
<a href="/pages/feeds" target="_blank" rel="noreferrer noopener">
<svg role="img" viewBox="0 0 24 24" class="w-4 h-4 mt-1.75 fill-current" aria-label="Follow our RSS feeds">
<title>RSS</title>
<path d="M19.199 24C19.199 13.467 10.533 4.8 0 4.8V0c13.165 0 24 10.835 24 24h-4.801zM3.291 17.415c1.814 0 3.293 1.479 3.293 3.295 0 1.813-1.485 3.29-3.301 3.29C1.47 24 0 22.526 0 20.71s1.475-3.294 3.291-3.295zM15.909 24h-4.665c0-6.169-5.075-11.245-11.244-11.245V8.09c8.727 0 15.909 7.184 15.909 15.91z"></path>
</svg>
</a>
</li>
<li class="twitter-icon">
<a href="https://twitter.com/DZoneInc" target="_blank" rel="noreferrer noopener">
<svg role="img" viewBox="0 0 24 24" aria-label="Follow us on X">
<title>X</title>
<path d="M14.234 10.162 22.977 0h-2.072l-7.591 8.824L7.251 0H.258l9.168 13.343L.258 24H2.33l8.016-9.318L16.749 24h6.993zm-2.837 3.299-.929-1.329L3.076 1.56h3.182l5.965 8.532.929 1.329 7.754 11.09h-3.182z"></path>
</svg>
</a>
</li>
<li class="facebook-icon">
<a href="https://www.facebook.com/DZoneInc" target="_blank" rel="noreferrer noopener">
<svg role="img" viewBox="0 0 24 24" aria-label="Follow us on Facebook">
<title>Facebook</title>
<path d="M9.101 23.691v-7.98H6.627v-3.667h2.474v-1.58c0-4.085 1.848-5.978 5.858-5.978.401 0 .955.042 1.468.103a8.68 8.68 0 0 1 1.141.195v3.325a8.623 8.623 0 0 0-.653-.036 26.805 26.805 0 0 0-.733-.009c-.707 0-1.259.096-1.675.309a1.686 1.686 0 0 0-.679.622c-.258.42-.374.995-.374 1.752v1.297h3.919l-.386 2.103-.287 1.564h-3.246v8.245C19.396 23.238 24 18.179 24 12.044c0-6.627-5.373-12-12-12s-12 5.373-12 12c0 5.628 3.874 10.35 9.101 11.647Z"></path>
</svg>
</a>
</li>
<li class="linkedin-icon">
<a href="https://www.linkedin.com/company/dzone/" target="_blank"
rel="noreferrer noopener">
<svg viewBox="0 0 24 25" fill="none" aria-label="Follow us on LinkedIn">
<path d="M6.20062 21.2143H1.84688V7.194H6.20062V21.2143ZM4.02141 5.2815C2.62922 5.2815 1.5 4.12838 1.5 2.73619C1.5 2.06747 1.76565 1.42614 2.2385 0.953285C2.71136 0.48043 3.35269 0.214783 4.02141 0.214783C4.69012 0.214783 5.33145 0.48043 5.80431 0.953285C6.27716 1.42614 6.54281 2.06747 6.54281 2.73619C6.54281 4.12838 5.413 5.2815 4.02141 5.2815ZM22.4953 21.2143H18.1509V14.3893C18.1509 12.7628 18.1181 10.6768 15.8873 10.6768C13.6237 10.6768 13.2769 12.444 13.2769 14.2721V21.2143H8.92781V7.194H13.1034V9.1065H13.1644C13.7456 8.00494 15.1655 6.84244 17.2838 6.84244C21.69 6.84244 22.5 9.744 22.5 13.5128V21.2143H22.4953Z" fill="currentColor"></path>
</svg>
</a>
</li>
</ul>
</div>
<div class="top-section col-xs-12">
<div class="col-xs-12 col-sm-6">
<p class="section-header">ABOUT US</p>
<ul class="link-group">
<li><a href="/pages/about" rel="noreferrer noopener">About DZone</a></li>
<li><a href="/cdn-cgi/l/email-protection#11626461617e636551756b7e7f743f727e7c" rel="noreferrer noopener">Support and feedback</a></li>
<li><a href="/pages/dzone-community-research">Community research</a></li>
</ul>
</div>
<div class="col-xs-12 col-sm-6">
<p class="section-header">ADVERTISE</p>
<ul class="link-group">
<li><a href="https://advertise.dzone.com" target="_blank" rel="noreferrer noopener">Advertise with DZone</a></li>
</ul>
</div>
</div>
<div class="bottom-section col-xs-12">
<div class="col-xs-12 col-sm-6">
<p class="section-header">CONTRIBUTE ON DZONE</p>
<ul class="bottom-top-list link-group">
<li><a href="/articles/dzones-article-submission-guidelines">Article Submission Guidelines</a></li>
<li><a href="/pages/contribute" rel="noreferrer noopener">Become a Contributor</a></li>
<li><a href="/pages/core" rel="noreferrer noopener">Core Program</a></li>
<li><a href="/writers-zone" rel="noreferrer noopener">Visit the Writers' Zone</a></li>
</ul>
<p class="section-header">LEGAL</p>
<ul class="link-group">
<li><a href="https://technologyadvice.com/terms-conditions/" target="_blank" rel="noreferrer noopener">Terms of Service</a></li>
<li><a href="https://technologyadvice.com/privacy-policy/" target="_blank" rel="noreferrer noopener">Privacy Policy</a></li>
</ul>
</div>
<div class="col-xs-12 col-sm-6">
<p class="section-header">CONTACT US</p>
<ul class="link-group">
<li>3343 Perimeter Hill Drive</li>
<li>Suite 215</li>
<li>Nashville, TN 37211</li>
<li><a href="/cdn-cgi/l/email-protection#a5d6d0d5d5cad7d1e5c1dfcacbc08bc6cac8" rel="noreferrer noopener"><span class="__cf_email__" data-cfemail="087b7d7878677a7c486c7267666d266b6765">[email&#160;protected]</span></a></li>
</ul>
</div>
</div>
</div>
<div class="right col-xs-12 col-sm-5">
<p class="connect-text">Let's be friends:</p>
<div class="col-xs-12 social-media-icons footer-wide">
<ul class="icons-only">
<li class="rss-icon" id="rss-footer-1">
<a href="/pages/feeds" target="_blank" rel="noreferrer noopener">
<svg role="img" viewBox="0 0 24 24" aria-label="Follow our RSS feeds">
<title>RSS</title>
<path d="M19.199 24C19.199 13.467 10.533 4.8 0 4.8V0c13.165 0 24 10.835 24 24h-4.801zM3.291 17.415c1.814 0 3.293 1.479 3.293 3.295 0 1.813-1.485 3.29-3.301 3.29C1.47 24 0 22.526 0 20.71s1.475-3.294 3.291-3.295zM15.909 24h-4.665c0-6.169-5.075-11.245-11.244-11.245V8.09c8.727 0 15.909 7.184 15.909 15.91z"></path>
</svg>
</a>
</li>
<li class="twitter-icon">
<a href="https://twitter.com/DZoneInc" target="_blank" rel="noreferrer noopener">
<svg role="img" viewBox="0 0 24 24" aria-label="Follow us on X">
<title>X</title>
<path d="M14.234 10.162 22.977 0h-2.072l-7.591 8.824L7.251 0H.258l9.168 13.343L.258 24H2.33l8.016-9.318L16.749 24h6.993zm-2.837 3.299-.929-1.329L3.076 1.56h3.182l5.965 8.532.929 1.329 7.754 11.09h-3.182z"></path>
</svg>
</a>
</li>
<li class="facebook-icon">
<a href="https://www.facebook.com/DZoneInc" target="_blank" rel="noreferrer noopener">
<svg role="img" viewBox="0 0 24 24" aria-label="Follow us on Facebook">
<title>Facebook</title>
<path d="M9.101 23.691v-7.98H6.627v-3.667h2.474v-1.58c0-4.085 1.848-5.978 5.858-5.978.401 0 .955.042 1.468.103a8.68 8.68 0 0 1 1.141.195v3.325a8.623 8.623 0 0 0-.653-.036 26.805 26.805 0 0 0-.733-.009c-.707 0-1.259.096-1.675.309a1.686 1.686 0 0 0-.679.622c-.258.42-.374.995-.374 1.752v1.297h3.919l-.386 2.103-.287 1.564h-3.246v8.245C19.396 23.238 24 18.179 24 12.044c0-6.627-5.373-12-12-12s-12 5.373-12 12c0 5.628 3.874 10.35 9.101 11.647Z"></path>
</svg>
</a>
</li>
<li class="linkedin-icon">
<a href="https://www.linkedin.com/company/dzone/" target="_blank"
rel="noreferrer noopener">
<svg viewBox="0 0 24 25" fill="none" aria-label="Follow us on LinkedIn">
<path d="M6.20062 21.2143H1.84688V7.194H6.20062V21.2143ZM4.02141 5.2815C2.62922 5.2815 1.5 4.12838 1.5 2.73619C1.5 2.06747 1.76565 1.42614 2.2385 0.953285C2.71136 0.48043 3.35269 0.214783 4.02141 0.214783C4.69012 0.214783 5.33145 0.48043 5.80431 0.953285C6.27716 1.42614 6.54281 2.06747 6.54281 2.73619C6.54281 4.12838 5.413 5.2815 4.02141 5.2815ZM22.4953 21.2143H18.1509V14.3893C18.1509 12.7628 18.1181 10.6768 15.8873 10.6768C13.6237 10.6768 13.2769 12.444 13.2769 14.2721V21.2143H8.92781V7.194H13.1034V9.1065H13.1644C13.7456 8.00494 15.1655 6.84244 17.2838 6.84244C21.69 6.84244 22.5 9.744 22.5 13.5128V21.2143H22.4953Z" fill="currentColor"></path>
</svg>
</a>
</li>
</ul>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
<script data-cfasync="false" src="/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js"></script><script>
const articleId = 3494925;
const likes = 1;
const assetDomain = 'https://dz2cdn1.dzone.com';
const codemirrorVars = {
modeURI: 'https://dz2cdn1.dzone.com/themes/dz20/lib/codemirror/mode/',
requiredScripts: [
'https://dz2cdn1.dzone.com/themes/dz20/lib/codemirror/lib/codemirror.js',
'https://dz2cdn1.dzone.com/themes/dz20/lib/codemirror/addon/mode/overlay.js',
'https://dz2cdn1.dzone.com/themes/dz20/lib/codemirror/addon/mode/multiplex.js',
'https://dz2cdn1.dzone.com/themes/dz20/lib/codemirror/mode/meta.js'
]
};
const gptTags = {
'zone': 'Databases',
'topicTag': 'MySQL,CATS,Performance',
'company': '',
'siteSection': 'Zones',
'articleCategory': 'analysis',
'nodeID': '3494925',
'authorID': '5200737',
'publishYear': '2025',
'publishMonth': '04',
'jobRole': '',
'companySize': '',
'env': 'prod'
};
const minCommentChar = 10;
</script>
<script async>const width = window.innerWidth;
const metadata = {
'top': {
'position': 'top',
'slot': 'dz2_article_billboard_new',
},
'sponsorLogo': {
'position': 'zoneHomepage',
'slot': 'dz2_homepage_sponsor_logo',
'refreshable': false
},
'sidebar1': {
'position': 'sidebar',
'slot': 'dz2_article_halfpage_new',
'minWidthToShow': 1024
},
'topBumper': {
'position': 'top',
'slot': 'dz2_bumper_text_ad',
'minWidthToShow': 1024
},
'bottomBumper': {
'position': 'bottom',
'slot': 'dz2_bumper_text_ad',
'minWidthToShow': 1024
},
'bottom': {
'position': 'bottom',
'slot': 'dz2_article_bottom',
},
'bottomStickyFooter': {
'position': 'sticky',
'slot': 'dz2_sticky_footer_leaderboard',
},
'partner': {
'slot': 'dz2_partner_resource_link',
},
'branded': {
'slot': 'dz2_branded_content',
'refreshable': false
},
'topicBillboard': {
'position': ['top', 'zoneHomepage'],
'slot': 'dz2_topic_billboard',
},
'listPageSidebar': {
'position': 'sidebar',
'slot': 'dz2_list_page_sidebar',
'minWidthToShow': 1024
},
'topListPageLeaderboard2': {
'position': ['top', 'zoneList'],
'slot': 'dz2_list_page_leaderboard_2',
},
'bottomListPageLeaderboard2': {
'position': ['bottom', 'zoneList'],
'slot': 'dz2_list_page_leaderboard_2',
},
'homepageLeaderboard': {
'position': 'top',
'slot': 'dz2_homepage_leaderboard',
},
'homepageLeaderboard2': {
'position': 'bottom',
'slot': 'dz2_homepage_leaderboard_2',
},
'skybox': {
'position': 'above nav',
'slot': 'dz_skybox',
'refreshable': false
},
'inline': {
'position': 'inline',
'slot': 'dz2_inline-article-display',
}
};
var campaign = new URLSearchParams(window.location.search).get("adTargeting_campaign");
window.googletag = window.googletag || { cmd: [] };
if (campaign) {
window.googletag.cmd.push(function() {
window.googletag.setConfig({ targeting: { campaign }});
});
}
let lastHeader = null;
const topContainer = document.querySelector('#top-bumper-container');
const bottomContainer = document.querySelector('#bottom-bumper-container');
function GAM_getPersistentValue(key) {
const stored = JSON.parse(localStorage.getItem(key));
if (!stored) {
return null;
}
const { value, expiration } = stored;
if (expiration && Date.now() >= expiration) {
localStorage.removeItem(key);
return null;
}
return value;
}
function GAM_setPersistentValue(key, value, expiration) {
// 5 minutes from now
if (!expiration) {
expiration = Date.now() + 300000;
}
const storedValue = JSON.stringify({
value: value,
expiration: expiration
});
localStorage.setItem(key, storedValue);
return value;
}
function GAM_synchronousRequest(params) {
const xhr = new XMLHttpRequest();
xhr.open('GET', params.url, false);
xhr.setRequestHeader("Content-Type", "application/json");
if (typeof params.auth_header !== "undefined") {
xhr.setRequestHeader("Authorization", params.auth_header);
}
xhr.send(null);
if (xhr.status === 200) {
return xhr.responseText;
} else {
throw new Error('Request failed: ' + xhr.statusText);
}
}
function GAM_fetch_data(params) {
let stored_data = GAM_getPersistentValue(params.storage_key);
if (stored_data === null) {
try {
const response = GAM_synchronousRequest(params);
const data = JSON.parse(response);
// Store and expire after 30 minutes
return GAM_setPersistentValue(params.storage_key, data, Date.now() + 1800000);
} catch (error) {
console.error('Could not get ' + params.storage_key + ' data: ' + error);
return null;
}
} else {
return stored_data;
}
}
function GAM_setUpSixSenseTargeting() {
let meData = GAM_fetch_data({
url: "https://link.technologyadvice.com/_me",
storage_key: "ta_me_data"
});
let sixSenseData = GAM_fetch_data({
url: "https://epsilon.6sense.com/v3/company/details",
auth_header: "Token d20a1b0e892442270cbc4cb6801c0160d28af04c",
storage_key: "ta_6s_data"
});
function meDataIncludes(i) {
return meData.tags.includes(i);
}
if (typeof meData !== "undefined" && meData !== null) {
window.googletag.pubads().setTargeting("visitor_id", meData.vid);
window.googletag.pubads().setTargeting("user_agent", meData.user_agent);
var tags_mapping = {
"is_datacenter": ["site.is-datacenter"],
"is_suspected_bot": ["site.suspected-bad-bot", "site.bad-bot"],
"is_ta_user": ["site.is-ta-user"],
"is_crawler": ["site.user-agent-blocked"],
"is_ad_blocked": ["site.is-ad-blocked"],
};
for (var key in tags_mapping) {
if (tags_mapping[key].some(meDataIncludes)) {
window.googletag.pubads().setTargeting(key, 'true');
}
}
}
if (typeof sixSenseData !== "undefined" && sixSenseData !== null) {
var segment_ids = [];
if (sixSenseData.segments && sixSenseData.segments.ids && sixSenseData.segments.ids.length) {
sixSenseData.segments.ids.forEach(function (v) {
segment_ids.push(v.toString());
});
}
if (typeof segment_ids !== "undefined" && segment_ids.length > 0) {
window.googletag.pubads().setTargeting("segment_ids_6si", segment_ids);
}
}
}
if (width >= 1024 && (topContainer || bottomContainer)) {
// Dynamically create bumper ad slots for non-mobile devices.
// Prevents ugly dividers being rendered on empty ad slots (mobile)
const topBumper = document.createElement('div');
topBumper.id = 'div-gpt-ad-1435246566686-3';
topBumper.classList.add('article-bumper', 'article-bumper-top', 'dz2_bumper_text_ad');
topBumper.setAttribute('data-gpt-slot', 'topBumper');
topContainer.appendChild(topBumper);
const bottomBumper = document.createElement('div');
bottomBumper.id = 'div-gpt-ad-1435246566686-4';
bottomBumper.classList.add('article-bumper', 'article-bumper-bottom', 'dz2_bumper_text_ad');
bottomBumper.setAttribute('data-gpt-slot', 'bottomBumper');
bottomContainer.appendChild(bottomBumper);
}
if (gptTags.zone) {
gptTags.zone = gptTags.zone.replaceAll(/[\s/]/g, '_')
.replaceAll(/[^a-zA-Z0-9_]/g, '')
.toLowerCase();
}
makeAds();
function handleSkybox() {
const skybox = document.querySelector('div.skybox');
if (skybox) {
document.body.classList.add('skybox-auto-collapse');
// observe classlist changes for offsetting sticky ads
const observer = new MutationObserver((mutations) => {
mutations.forEach((mutation) => {
if (mutation.type === 'attributes' && mutation.attributeName === 'class') {
let offset = 0;
if (!document.body.classList.contains('skybox-closed') && (
document.body.classList.contains('ccad-skybox-manualcollapse')
|| document.body.classList.contains('ccad-skybox-manualexpand')
)) {
offset = skybox.getBoundingClientRect().height;
}
let eligibleAds = [
{ element: document.querySelector('.content-right-images'), offset: 108 },
{ element: document.querySelector('.trending-sidebar'), offset: 88 },
{ element: document.querySelector('.trending'), offset: 88 }
];
for (let ad of eligibleAds) {
if (ad.element) {
ad.element.style.top = (ad.offset + offset) + 'px';
}
}
}
});
});
observer.observe(document.body, { attributes: true });
}
}
function isHeaderEligible(header) {
const range = document.createRange();
range.setStartAfter(lastHeader);
range.setEndBefore(header);
return range.toString().trim().length >= 600;
}
function placeInlineAds() {
const excludedContent = document.querySelectorAll('#ftl-article.branded-content, #ftl-article.sponsored');
if (excludedContent.length > 0) {
return;
}
const headers = Array.from(document.querySelectorAll('.content-html h2')).splice(1);
let globalIndex = 12;
for (let i = 0; i < headers.length; i++) {
if (!lastHeader || isHeaderEligible(headers[i])) {
const element = document.createElement('div');
element.id = 'div-gpt-ad-1435246566686-' + globalIndex;
element.classList.add('inline-display', 'dz2_inline-article-display');
element.setAttribute('data-gpt-slot', 'inline');
headers[i].before(element);
lastHeader = element;
globalIndex++;
}
}
}
function makeAds() {
handleSkybox();
placeInlineAds();
const script = document.createElement('script');
script.src = 'https://i6ByW9Zmz4ncxhHkb.ay.delivery/manager/i6ByW9Zmz4ncxhHkb';
script.type = 'text/javascript';
script.referrerPolicy = 'no-referrer-when-downgrade';
document.head.appendChild(script);
window.googletag.cmd.push(function() {
const containers = document.querySelectorAll('div[data-gpt-slot]');
for (let container of containers) {
const div = container.getAttribute('data-gpt-slot');
const meta = metadata[div];
if (meta.minWidthToShow && width < meta.minWidthToShow) {
continue;
}
window.googletag.pubads().setTargeting('hostname', window.location.hostname);
Object.keys(gptTags).forEach(function(key) {
window.googletag.pubads().setTargeting(key, gptTags[key]);
});
window.googletag.pubads().addEventListener('slotRenderEnded', (event) => {
window.requestAnimationFrame(() => {
var slotId = event.slot.getSlotElementId();
if (!slotId.includes('__ayManagerEnv__')) {
return;
}
var className = slotId.split('__ayManagerEnv__')[0];
var slotName = className.replace('dz2_', '').replace('dz_', '').replace(/_\d+$/, '');
var unitName = meta.slot.replace('dz2_', '').replace('dz_', '').replace(/_\d+$/, '');
if (slotName !== unitName) {
return;
}
var elem = document.getElementById(slotId);
if (!elem) {
console.warn('Ad element missing', slotId);
return;
}
// Ad unit did not fill, collapse slot
if (event.isEmpty && elem.parentElement) {
elem.parentElement.style.display = 'none';
}
});
});
}
GAM_setUpSixSenseTargeting();
});
}
</script>
<script async>// InMobi Choice. Consent Manager Tag v3.0 (for TCF 2.2)
!function(){var e=window.location.hostname,t=document.createElement("script"),n=document.getElementsByTagName("script")[0],a="https://cmp.inmobi.com".concat("/choice/","vPn77x7pBG57Y","/","dzone.com","/choice.js?tag_version=V3"),p=0;t.async=!0,t.type="text/javascript",t.src=a,n.parentNode.insertBefore(t,n),function(){for(var e,t="__tcfapiLocator",n=[],a=window;a;){try{if(a.frames[t]){e=a;break}}catch(e){}if(a===window.top)break;a=a.parent}e||(!function e(){var n=a.document,p=!!a.frames[t];if(!p)if(n.body){var s=n.createElement("iframe");s.style.cssText="display:none",s.name=t,n.body.appendChild(s)}else setTimeout(e,5);return!p}(),a.__tcfapi=function(){var e,t=arguments;if(!t.length)return n;if("setGdprApplies"===t[0])t.length>3&&2===t[2]&&"boolean"==typeof t[3]&&(e=t[3],"function"==typeof t[2]&&t[2]("set",!0));else if("ping"===t[0]){var a={gdprApplies:e,cmpLoaded:!1,cmpStatus:"stub"};"function"==typeof t[2]&&t[2](a)}else"init"===t[0]&&"object"==typeof t[3]&&(t[3]=Object.assign(t[3],{tag_version:"V3"})),n.push(t)},a.addEventListener("message",(function(e){var t="string"==typeof e.data,n={};try{n=t?JSON.parse(e.data):e.data}catch(e){}var a=n.__tcfapiCall;a&&window.__tcfapi(a.command,a.version,(function(n,p){var s={__tcfapiReturn:{returnValue:n,success:p,callId:a.callId}};t&&(s=JSON.stringify(s)),e&&e.source&&e.source.postMessage&&e.source.postMessage(s,"*")}),a.parameter)}),!1))}(),function(){const e=["2:tcfeuv2","6:uspv1","7:usnatv1","8:usca","9:usvav1","10:uscov1","11:usutv1","12:usctv1"];window.__gpp_addFrame=function(e){if(!window.frames[e])if(document.body){var t=document.createElement("iframe");t.style.cssText="display:none",t.name=e,document.body.appendChild(t)}else window.setTimeout(window.__gpp_addFrame,10,e)},window.__gpp_stub=function(){var t=arguments;if(__gpp.queue=__gpp.queue||[],__gpp.events=__gpp.events||[],!t.length||1==t.length&&"queue"==t[0])return __gpp.queue;if(1==t.length&&"events"==t[0])return __gpp.events;var n=t[0],a=t.length>1?t[1]:null,p=t.length>2?t[2]:null;if("ping"===n)a({gppVersion:"1.1",cmpStatus:"stub",cmpDisplayStatus:"hidden",signalStatus:"not ready",supportedAPIs:e,cmpId:10,sectionList:[],applicableSections:[-1],gppString:"",parsedSections:{}},!0);else if("addEventListener"===n){"lastId"in __gpp||(__gpp.lastId=0),__gpp.lastId++;var s=__gpp.lastId;__gpp.events.push({id:s,callback:a,parameter:p}),a({eventName:"listenerRegistered",listenerId:s,data:!0,pingData:{gppVersion:"1.1",cmpStatus:"stub",cmpDisplayStatus:"hidden",signalStatus:"not ready",supportedAPIs:e,cmpId:10,sectionList:[],applicableSections:[-1],gppString:"",parsedSections:{}}},!0)}else if("removeEventListener"===n){for(var i=!1,o=0;o<__gpp.events.length;o++)if(__gpp.events[o].id==p){__gpp.events.splice(o,1),i=!0;break}a({eventName:"listenerRemoved",listenerId:p,data:i,pingData:{gppVersion:"1.1",cmpStatus:"stub",cmpDisplayStatus:"hidden",signalStatus:"not ready",supportedAPIs:e,cmpId:10,sectionList:[],applicableSections:[-1],gppString:"",parsedSections:{}}},!0)}else"hasSection"===n?a(!1,!0):"getSection"===n||"getField"===n?a(null,!0):__gpp.queue.push([].slice.apply(t))},window.__gpp_msghandler=function(e){var t="string"==typeof e.data;try{var n=t?JSON.parse(e.data):e.data}catch(e){n=null}if("object"==typeof n&&null!==n&&"__gppCall"in n){var a=n.__gppCall;window.__gpp(a.command,(function(n,p){var s={__gppReturn:{returnValue:n,success:p,callId:a.callId}};e.source.postMessage(t?JSON.stringify(s):s,"*")}),"parameter"in a?a.parameter:null,"version"in a?a.version:"1.1")}},"__gpp"in window&&"function"==typeof window.__gpp||(window.__gpp=window.__gpp_stub,window.addEventListener("message",window.__gpp_msghandler,!1),window.__gpp_addFrame("__gppLocator"))}();var s=function(){var e=arguments;typeof window.__uspapi!==s&&setTimeout((function(){void 0!==window.__uspapi&&window.__uspapi.apply(window.__uspapi,e)}),500)};if(void 0===window.__uspapi){window.__uspapi=s;var i=setInterval((function(){p++,window.__uspapi===s&&p<3?console.warn("USP is not accessible"):clearInterval(i)}),6e3)}}();
</script>
<script async>
(function(w, d, s, l, i) {
w[l] = w[l] || [];
w[l].push({'gtm.start': new Date().getTime(), event: 'gtm.js'});
var f = d.getElementsByTagName(s)[0], j = d.createElement(s), dl = l != 'dataLayer' ? '&l=' + l : '';
j.async = true;
j.src = 'https://www.googletagmanager.com/gtm.js?id=' + i + dl;
f.parentNode.insertBefore(j,f);
})(window, document, 'script', 'dataLayer', 'GTM-K25QL22');
</script>
<script>
window.ga=window.ga||function(){(ga.q=ga.q||[]).push(arguments)};ga.l=+new Date;
ga('create', 'UA-410289-1', 'auto');
ga('require', 'linkid', 'linkid.js');
ga('require', 'GTM-TSD9TZP');
ga('set', 'siteSpeedSampleRate', 25);
</script>
<script async src="https://www.google-analytics.com/analytics.js"></script>
<script async>var analytics = {
'dimension1': 'Databases',
'dimension2': 'article/analysis',
'dimension3': '2025-04-08',
'dimension4': '0',
'dimension5': '',
'dimension7': 'MySQL, CATS, Performance',
'dimension8': 'wangbin579',
'dimension9': 'undefined',
'dimension10': 'NULL'
};
if (window.ga) {
Object.keys(analytics).forEach(function(key) {
window.ga('set', key, analytics[key]);
});
window.ga('send', 'pageview');
}</script>
<script src="https://dz2cdn1.dzone.com/themes/dz20/lib/static/jquery/jquery.min.js"></script>
<script async src="https://dz2cdn1.dzone.com/themes/dz20/lib/static/bootstrap/bootstrap.min.js"></script>
<script>
function loadScript(src) {
return new Promise(function (resolve, reject) {
const s = document.createElement('script');
s.src = src;
s.onload = resolve;
s.onerror = reject;
document.head.appendChild(s);
});
}
function loadStyle(href) {
const link = document.createElement('link');
link.rel = 'stylesheet';
link.href = href;
document.head.appendChild(link);
}
function loadScriptsSync(deferred) {
var p = Promise.resolve();
for (var i = 0; i < deferred.length; i++) {
let script = deferred[i];
p = p.then(function() {
return loadScript(script);
});
}
return p;
}
function loadStyles() {
const deferred = [
'https://dz2cdn1.dzone.com/themes/dz20/lib/codemirror/lib/codemirror.css',
'https://dz2cdn1.dzone.com/themes/dz20/ftl/comments/styles.css',
'https://dz2cdn1.dzone.com/themes/dz20/lib/froala3/css/froala_editor.pkgd.min.css',
'https://dz2cdn1.dzone.com/themes/dz20/lib/froala3/css/themes/gray.min.css',
'https://dz2cdn1.dzone.com/themes/dz20/ftl/article/mini-profile.css'
];
for (var i = 0; i < deferred.length; i++) {
loadStyle(deferred[i]);
}
}
window.addEventListener('load', function(_event) {
loadStyles();
loadScriptsSync([
'https://dz2cdn1.dzone.com/themes/dz20/lib/lazysizes.min.js',
'https://dz2cdn1.dzone.com/themes/dz20/ftl/article/codeblocks.js',
'https://dz2cdn1.dzone.com/themes/dz20/ftl/article/activity-bar.js',
'https://dz2cdn1.dzone.com/themes/dz20/lib/froala3/js/froala_editor.pkgd.min.js',
'https://dz2cdn1.dzone.com/themes/dz20/ftl/froala/content.js',
'https://dz2cdn1.dzone.com/themes/dz20/ftl/comments/content.js',
'https://dz2cdn1.dzone.com/themes/dz20/ftl/article/content.js'
]);
});
</script>
</body>
</html>