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| author | Peter Eisentraut <peter@eisentraut.org> | 2024-08-28 07:26:48 +0200 |
|---|---|---|
| committer | Peter Eisentraut <peter@eisentraut.org> | 2024-08-28 07:28:27 +0200 |
| commit | 6654bb92047b37cee053cedd6fa1829841b2ad8e (patch) | |
| tree | ae3b84ab5a8e4581ac6f15b9afe68641ec554bee /doc/src | |
| parent | 2e6a8047f0c94b4ac1c3e80faecd628ae552a6c3 (diff) | |
| download | postgresql-6654bb92047b37cee053cedd6fa1829841b2ad8e.tar.gz postgresql-6654bb92047b37cee053cedd6fa1829841b2ad8e.zip | |
Add prefetching support on macOS
macOS doesn't have posix_fadvise(), but fcntl() with the F_RDADVISE
command does the same thing.
Some related documentation has been generalized to not mention
posix_advise() specifically anymore.
Reviewed-by: Thomas Munro <thomas.munro@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/0827edec-1317-4917-a186-035eb1e3241d%40eisentraut.org
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> |