diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/config.sgml | 33 |
1 files changed, 32 insertions, 1 deletions
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml index 1966ecc162c..091a79d4f36 100644 --- a/doc/src/sgml/config.sgml +++ b/doc/src/sgml/config.sgml @@ -3172,7 +3172,6 @@ include_dir 'conf.d' </listitem> </itemizedlist> <para> - The <literal>open_</literal>* options also use <literal>O_DIRECT</literal> if available. Not all of these choices are available on all platforms. The default is the first method in the above list that is supported by the platform, except that <literal>fdatasync</literal> is the default on @@ -11256,6 +11255,38 @@ dynamic_library_path = 'C:\tools\postgresql;H:\my_project\lib;$libdir' </listitem> </varlistentry> + <varlistentry id="guc-io-direct" xreflabel="io_direct"> + <term><varname>io_direct</varname> (<type>string</type>) + <indexterm> + <primary><varname>io_direct</varname> configuration parameter</primary> + </indexterm> + </term> + <listitem> + <para> + Ask the kernel to minimize caching effects for relation data and WAL + files using <literal>O_DIRECT</literal> (most Unix-like systems), + <literal>F_NOCACHE</literal> (macOS) or + <literal>FILE_FLAG_NO_BUFFERING</literal> (Windows). + </para> + <para> + May be set to an empty string (the default) to disable use of direct + I/O, or a comma-separated list of operations that should use direct I/O. + The valid options are <literal>data</literal> for + main data files, <literal>wal</literal> for WAL files, and + <literal>wal_init</literal> for WAL files when being initially + allocated. + </para> + <para> + Some operating systems and file systems do not support direct I/O, so + non-default settings may be rejected at startup or cause errors. + </para> + <para> + Currently this feature reduces performance, and is intended for + developer testing only. + </para> + </listitem> + </varlistentry> + <varlistentry id="guc-post-auth-delay" xreflabel="post_auth_delay"> <term><varname>post_auth_delay</varname> (<type>integer</type>) <indexterm> |