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diff --git a/doc/src/sgml/html/logical-replication.html b/doc/src/sgml/html/logical-replication.html new file mode 100644 index 0000000..7cf69c4 --- /dev/null +++ b/doc/src/sgml/html/logical-replication.html @@ -0,0 +1,55 @@ +<?xml version="1.0" encoding="UTF-8" standalone="no"?> +<!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 31. Logical Replication</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="wal-internals.html" title="30.6. WAL Internals" /><link rel="next" href="logical-replication-publication.html" title="31.1. Publication" /></head><body id="docContent" class="container-fluid col-10"><div xmlns="http://www.w3.org/TR/xhtml1/transitional" class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">Chapter 31. Logical Replication</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="wal-internals.html" title="30.6. WAL Internals">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="admin.html" title="Part III. Server Administration">Up</a></td><th width="60%" align="center">Part III. Server Administration</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 14.5 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="logical-replication-publication.html" title="31.1. Publication">Next</a></td></tr></table><hr></hr></div><div class="chapter" id="LOGICAL-REPLICATION"><div class="titlepage"><div><div><h2 class="title">Chapter 31. Logical Replication</h2></div></div></div><div class="toc"><p><strong>Table of Contents</strong></p><dl class="toc"><dt><span class="sect1"><a href="logical-replication-publication.html">31.1. Publication</a></span></dt><dt><span class="sect1"><a href="logical-replication-subscription.html">31.2. Subscription</a></span></dt><dd><dl><dt><span class="sect2"><a href="logical-replication-subscription.html#LOGICAL-REPLICATION-SUBSCRIPTION-SLOT">31.2.1. Replication Slot Management</a></span></dt></dl></dd><dt><span class="sect1"><a href="logical-replication-conflicts.html">31.3. Conflicts</a></span></dt><dt><span class="sect1"><a href="logical-replication-restrictions.html">31.4. Restrictions</a></span></dt><dt><span class="sect1"><a href="logical-replication-architecture.html">31.5. Architecture</a></span></dt><dd><dl><dt><span class="sect2"><a href="logical-replication-architecture.html#LOGICAL-REPLICATION-SNAPSHOT">31.5.1. Initial Snapshot</a></span></dt></dl></dd><dt><span class="sect1"><a href="logical-replication-monitoring.html">31.6. Monitoring</a></span></dt><dt><span class="sect1"><a href="logical-replication-security.html">31.7. Security</a></span></dt><dt><span class="sect1"><a href="logical-replication-config.html">31.8. Configuration Settings</a></span></dt><dt><span class="sect1"><a href="logical-replication-quick-setup.html">31.9. Quick Setup</a></span></dt></dl></div><p> + Logical replication is a method of replicating data objects and their + changes, based upon their replication identity (usually a primary key). We + use the term logical in contrast to physical replication, which uses exact + block addresses and byte-by-byte replication. PostgreSQL supports both + mechanisms concurrently, see <a class="xref" href="high-availability.html" title="Chapter 27. High Availability, Load Balancing, and Replication">Chapter 27</a>. Logical + replication allows fine-grained control over both data replication and + security. + </p><p> + Logical replication uses a <em class="firstterm">publish</em> + and <em class="firstterm">subscribe</em> model with one or + more <em class="firstterm">subscribers</em> subscribing to one or more + <em class="firstterm">publications</em> on a <em class="firstterm">publisher</em> + node. Subscribers pull data from the publications they subscribe to and may + subsequently re-publish data to allow cascading replication or more complex + configurations. + </p><p> + Logical replication of a table typically starts with taking a snapshot + of the data on the publisher database and copying that to the subscriber. + Once that is done, the changes on the publisher are sent to the subscriber + as they occur in real-time. The subscriber applies the data in the same + order as the publisher so that transactional consistency is guaranteed for + publications within a single subscription. This method of data replication + is sometimes referred to as transactional replication. + </p><p> + The typical use-cases for logical replication are: + + </p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p> + Sending incremental changes in a single database or a subset of a + database to subscribers as they occur. + </p></li><li class="listitem"><p> + Firing triggers for individual changes as they arrive on the + subscriber. + </p></li><li class="listitem"><p> + Consolidating multiple databases into a single one (for example for + analytical purposes). + </p></li><li class="listitem"><p> + Replicating between different major versions of PostgreSQL. + </p></li><li class="listitem"><p> + Replicating between PostgreSQL instances on different platforms (for + example Linux to Windows) + </p></li><li class="listitem"><p> + Giving access to replicated data to different groups of users. + </p></li><li class="listitem"><p> + Sharing a subset of the database between multiple databases. + </p></li></ul></div><p> + </p><p> + The subscriber database behaves in the same way as any other PostgreSQL + instance and can be used as a publisher for other databases by defining its + own publications. When the subscriber is treated as read-only by + application, there will be no conflicts from a single subscription. On the + other hand, if there are other writes done either by an application or by other + subscribers to the same set of tables, conflicts can arise. + </p></div><div xmlns="http://www.w3.org/TR/xhtml1/transitional" class="navfooter"><hr></hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="wal-internals.html" title="30.6. WAL Internals">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="admin.html" title="Part III. Server Administration">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="logical-replication-publication.html" title="31.1. Publication">Next</a></td></tr><tr><td width="40%" align="left" valign="top">30.6. WAL Internals </td><td width="20%" align="center"><a accesskey="h" href="index.html" title="PostgreSQL 14.5 Documentation">Home</a></td><td width="40%" align="right" valign="top"> 31.1. Publication</td></tr></table></div></body></html>
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