index 8862f84412e3b0c059781379bbd9f1392aa4c246..44cc5d2116d257803a9421a13d6f2e6b2cc71e61 100644 (file)
@@ -198,11 +198,11 @@ protocol to make nodes agree on a serializable transactional order.
</varlistentry>
<varlistentry>
- <term>Statement-Based Replication Middleware</term>
+ <term>SQL-Based Replication Middleware</term>
<listitem>
<para>
- With statement-based replication middleware, a program intercepts
+ With SQL-based replication middleware, a program intercepts
every SQL query and sends it to one or all servers. Each server
operates independently. Read-write queries must be sent to all servers,
so that every server receives any changes. But read-only queries can be
@@ -279,19 +279,6 @@ protocol to make nodes agree on a serializable transactional order.
</listitem>
</varlistentry>
- <varlistentry>
- <term>Commercial Solutions</term>
- <listitem>
-
- <para>
- Because <productname>PostgreSQL</productname> is open source and easily
- extended, a number of companies have taken <productname>PostgreSQL</productname>
- and created commercial closed-source solutions with unique
- failover, replication, and load balancing capabilities.
- </para>
- </listitem>
- </varlistentry>
-
</variablelist>
<para>
@@ -302,28 +289,37 @@ protocol to make nodes agree on a serializable transactional order.
<table id="high-availability-matrix">
<title>High Availability, Load Balancing, and Replication Feature Matrix</title>
<tgroup cols="9">
+ <colspec colname="col1" colwidth="1.1*"/>
+ <colspec colname="col2" colwidth="1*"/>
+ <colspec colname="col3" colwidth="1*"/>
+ <colspec colname="col4" colwidth="1*"/>
+ <colspec colname="col5" colwidth="1*"/>
+ <colspec colname="col6" colwidth="1*"/>
+ <colspec colname="col7" colwidth="1*"/>
+ <colspec colname="col8" colwidth="1*"/>
+ <colspec colname="col9" colwidth="1*"/>
<thead>
<row>
<entry>Feature</entry>
- <entry>Shared Disk Failover</entry>
- <entry>File System Replication</entry>
+ <entry>Shared Disk</entry>
+ <entry>File System Repl.</entry>
<entry>Write-Ahead Log Shipping</entry>
- <entry>Logical Replication</entry>
- <entry>Trigger-Based Master-Standby Replication</entry>
- <entry>Statement-Based Replication Middleware</entry>
- <entry>Asynchronous Multimaster Replication</entry>
- <entry>Synchronous Multimaster Replication</entry>
+ <entry>Logical Repl.</entry>
+ <entry>Trigger-Based Repl.</entry>
+ <entry>SQL Repl. Middle-ware</entry>
+ <entry>Async. MM Repl.</entry>
+ <entry>Sync. MM Repl.</entry>
</row>
</thead>
<tbody>
<row>
- <entry>Most common implementations</entry>
+ <entry>Popular examples</entry>
<entry align="center">NAS</entry>
<entry align="center">DRBD</entry>
- <entry align="center">built-in streaming replication</entry>
- <entry align="center">built-in logical replication, pglogical</entry>
+ <entry align="center">built-in streaming repl.</entry>
+ <entry align="center">built-in logical repl., pglogical</entry>
<entry align="center">Londiste, Slony</entry>
<entry align="center">pgpool-II</entry>
<entry align="center">Bucardo</entry>
@@ -331,7 +327,7 @@ protocol to make nodes agree on a serializable transactional order.
</row>
<row>
- <entry>Communication method</entry>
+ <entry>Comm. method</entry>
<entry align="center">shared disk</entry>
<entry align="center">disk blocks</entry>
<entry align="center">WAL</entry>
@@ -485,6 +481,14 @@ protocol to make nodes agree on a serializable transactional order.
</variablelist>
+ <para>
+ It should also be noted that because <productname>PostgreSQL</productname>
+ is open source and easily extended, a number of companies have
+ taken <productname>PostgreSQL</productname> and created commercial
+ closed-source solutions with unique failover, replication, and load
+ balancing capabilities. These are not discussed here.
+ </para>
+
</sect1>