diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/config.sgml | 14 | ||||
| -rw-r--r-- | doc/src/sgml/wal.sgml | 4 |
2 files changed, 7 insertions, 11 deletions
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml index 2937384b001..12feac60874 100644 --- a/doc/src/sgml/config.sgml +++ b/doc/src/sgml/config.sgml @@ -2679,11 +2679,9 @@ include_dir 'conf.d' </para> <para> - Asynchronous I/O depends on an effective <function>posix_fadvise</function> - function, which some operating systems lack. If the function is not - present then setting this parameter to anything but zero will result - in an error. On some operating systems (e.g., Solaris), the function - is present but does not actually do anything. + Asynchronous I/O requires that the operating system supports issuing + read-ahead advice. If there is no operating system support then + setting this parameter to anything but zero will result in an error. </para> <para> @@ -3852,10 +3850,8 @@ include_dir 'conf.d' <literal>off</literal>, <literal>on</literal> and <literal>try</literal> (the default). The setting <literal>try</literal> enables - prefetching only if the operating system provides the - <function>posix_fadvise</function> function, which is currently used - to implement prefetching. Note that some operating systems provide the - function, but it doesn't do anything. + prefetching only if the operating system provides support for issuing + read-ahead advice. </para> <para> Prefetching blocks that will soon be needed can reduce I/O wait times diff --git a/doc/src/sgml/wal.sgml b/doc/src/sgml/wal.sgml index d5df65bc693..0ba0c930b78 100644 --- a/doc/src/sgml/wal.sgml +++ b/doc/src/sgml/wal.sgml @@ -841,8 +841,8 @@ The <xref linkend="guc-maintenance-io-concurrency"/> and <xref linkend="guc-wal-decode-buffer-size"/> settings limit prefetching concurrency and distance, respectively. By default, it is set to - <literal>try</literal>, which enables the feature on systems where - <function>posix_fadvise</function> is available. + <literal>try</literal>, which enables the feature on systems that support + issuing read-ahead advice. </para> </sect1> |