diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/config.sgml | 14 | ||||
| -rw-r--r-- | doc/src/sgml/install-windows.sgml | 2 | ||||
| -rw-r--r-- | doc/src/sgml/installation.sgml | 5 | ||||
| -rw-r--r-- | doc/src/sgml/standalone-profile.xsl | 4 |
4 files changed, 17 insertions, 8 deletions
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml index 3eee9883595..6098f6b0202 100644 --- a/doc/src/sgml/config.sgml +++ b/doc/src/sgml/config.sgml @@ -3128,23 +3128,27 @@ include_dir 'conf.d' </varlistentry> <varlistentry id="guc-wal-compression" xreflabel="wal_compression"> - <term><varname>wal_compression</varname> (<type>boolean</type>) + <term><varname>wal_compression</varname> (<type>enum</type>) <indexterm> <primary><varname>wal_compression</varname> configuration parameter</primary> </indexterm> </term> <listitem> <para> - When this parameter is <literal>on</literal>, the <productname>PostgreSQL</productname> + This parameter enables compression of WAL using the specified + compression method. + When enabled, the <productname>PostgreSQL</productname> server compresses full page images written to WAL when <xref linkend="guc-full-page-writes"/> is on or during a base backup. A compressed page image will be decompressed during WAL replay. - The default value is <literal>off</literal>. - Only superusers can change this setting. + The supported methods are <literal>pglz</literal> and + <literal>lz4</literal> (if <productname>PostgreSQL</productname> was + compiled with <option>--with-lz4</option>). The default value is + <literal>off</literal>. Only superusers can change this setting. </para> <para> - Turning this parameter on can reduce the WAL volume without + Enabling compression can reduce the WAL volume without increasing the risk of unrecoverable data corruption, but at the cost of some extra CPU spent on the compression during WAL logging and on the decompression during WAL replay. diff --git a/doc/src/sgml/install-windows.sgml b/doc/src/sgml/install-windows.sgml index 312edc6f7aa..ba794b8c934 100644 --- a/doc/src/sgml/install-windows.sgml +++ b/doc/src/sgml/install-windows.sgml @@ -299,7 +299,7 @@ $ENV{MSBFLAGS}="/m"; <term><productname>LZ4</productname></term> <listitem><para> Required for supporting <productname>LZ4</productname> compression - method for compressing the table data. Binaries and source can be + method for compressing table or WAL data. Binaries and source can be downloaded from <ulink url="https://github.com/lz4/lz4/releases"></ulink>. </para></listitem> diff --git a/doc/src/sgml/installation.sgml b/doc/src/sgml/installation.sgml index 3c0aa118c76..61d0bc8c43f 100644 --- a/doc/src/sgml/installation.sgml +++ b/doc/src/sgml/installation.sgml @@ -270,7 +270,8 @@ su - postgres <para> You need <productname>LZ4</productname>, if you want to support compression of data with this method; see - <xref linkend="guc-default-toast-compression"/>. + <xref linkend="guc-default-toast-compression"/> and + <xref linkend="guc-wal-compression"/>. </para> </listitem> @@ -980,7 +981,7 @@ build-postgresql: <para> Build with <productname>LZ4</productname> compression support. This allows the use of <productname>LZ4</productname> for - compression of table data. + compression of table and WAL data. </para> </listitem> </varlistentry> diff --git a/doc/src/sgml/standalone-profile.xsl b/doc/src/sgml/standalone-profile.xsl index 8bdf58632cd..d748076a058 100644 --- a/doc/src/sgml/standalone-profile.xsl +++ b/doc/src/sgml/standalone-profile.xsl @@ -52,6 +52,10 @@ variant without links and references to the main documentation. <xsl:text>the configuration parameter default_toast_compression</xsl:text> </xsl:template> +<xsl:template match="xref[@linkend='guc-wal-compression']"> + <xsl:text>the configuration parameter wal_compression</xsl:text> +</xsl:template> + <xsl:template match="xref[@linkend='install-windows']"> <xsl:text>the documentation</xsl:text> </xsl:template> |