codekingpro/portable-devtools

1<?xml version="1.0" encoding="UTF-8" standalone="no"?>2<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>Chapter 13. Concurrency Control</title><link rel="stylesheet" type="text/css" href="stylesheet.css" /><link rev="made" href="pgsql-docs@lists.postgresql.org" /><meta name="generator" content="DocBook XSL Stylesheets Vsnapshot" /><link rel="prev" href="textsearch-limitations.html" title="12.11. Limitations" /><link rel="next" href="mvcc-intro.html" title="13.1. Introduction" /></head><body id="docContent" class="container-fluid col-10"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">Chapter 13. Concurrency Control</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="textsearch-limitations.html" title="12.11. Limitations">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="sql.html" title="Part II. The SQL Language">Up</a></td><th width="60%" align="center">Part II. The SQL Language</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 16.3 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="mvcc-intro.html" title="13.1. Introduction">Next</a></td></tr></table><hr /></div><div class="chapter" id="MVCC"><div class="titlepage"><div><div><h2 class="title">Chapter 13. Concurrency Control</h2></div></div></div><div class="toc"><p><strong>Table of Contents</strong></p><dl class="toc"><dt><span class="sect1"><a href="mvcc-intro.html">13.1. Introduction</a></span></dt><dt><span class="sect1"><a href="transaction-iso.html">13.2. Transaction Isolation</a></span></dt><dd><dl><dt><span class="sect2"><a href="transaction-iso.html#XACT-READ-COMMITTED">13.2.1. Read Committed Isolation Level</a></span></dt><dt><span class="sect2"><a href="transaction-iso.html#XACT-REPEATABLE-READ">13.2.2. Repeatable Read Isolation Level</a></span></dt><dt><span class="sect2"><a href="transaction-iso.html#XACT-SERIALIZABLE">13.2.3. Serializable Isolation Level</a></span></dt></dl></dd><dt><span class="sect1"><a href="explicit-locking.html">13.3. Explicit Locking</a></span></dt><dd><dl><dt><span class="sect2"><a href="explicit-locking.html#LOCKING-TABLES">13.3.1. Table-Level Locks</a></span></dt><dt><span class="sect2"><a href="explicit-locking.html#LOCKING-ROWS">13.3.2. Row-Level Locks</a></span></dt><dt><span class="sect2"><a href="explicit-locking.html#LOCKING-PAGES">13.3.3. Page-Level Locks</a></span></dt><dt><span class="sect2"><a href="explicit-locking.html#LOCKING-DEADLOCKS">13.3.4. Deadlocks</a></span></dt><dt><span class="sect2"><a href="explicit-locking.html#ADVISORY-LOCKS">13.3.5. Advisory Locks</a></span></dt></dl></dd><dt><span class="sect1"><a href="applevel-consistency.html">13.4. Data Consistency Checks at the Application Level</a></span></dt><dd><dl><dt><span class="sect2"><a href="applevel-consistency.html#SERIALIZABLE-CONSISTENCY">13.4.1. Enforcing Consistency with Serializable Transactions</a></span></dt><dt><span class="sect2"><a href="applevel-consistency.html#NON-SERIALIZABLE-CONSISTENCY">13.4.2. Enforcing Consistency with Explicit Blocking Locks</a></span></dt></dl></dd><dt><span class="sect1"><a href="mvcc-serialization-failure-handling.html">13.5. Serialization Failure Handling</a></span></dt><dt><span class="sect1"><a href="mvcc-caveats.html">13.6. Caveats</a></span></dt><dt><span class="sect1"><a href="locking-indexes.html">13.7. Locking and Indexes</a></span></dt></dl></div><a id="id-1.5.12.2" class="indexterm"></a><p>3   This chapter describes the behavior of the4   <span class="productname">PostgreSQL</span> database system when two or5   more sessions try to access the same data at the same time.  The6   goals in that situation are to allow efficient access for all7   sessions while maintaining strict data integrity.  Every developer8   of database applications should be familiar with the topics covered9   in this chapter.10  </p></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="textsearch-limitations.html" title="12.11. Limitations">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="sql.html" title="Part II. The SQL Language">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="mvcc-intro.html" title="13.1. Introduction">Next</a></td></tr><tr><td width="40%" align="left" valign="top">12.11. Limitations </td><td width="20%" align="center"><a accesskey="h" href="index.html" title="PostgreSQL 16.3 Documentation">Home</a></td><td width="40%" align="right" valign="top"> 13.1. Introduction</td></tr></table></div></body></html>