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| author | Bruce Momjian <bruce@momjian.us> | 2002-11-15 02:44:57 +0000 |
|---|---|---|
| committer | Bruce Momjian <bruce@momjian.us> | 2002-11-15 02:44:57 +0000 |
| commit | 2986aa6a668bce3cfb83606bb52e9d01ae66ad6c (patch) | |
| tree | 52b950f9d8ae7775cd24067866ecf1a0e265e821 /doc/src | |
| parent | 3779f7fd9fed8e77cb02a3ef26ab4311906377ad (diff) | |
| download | postgresql-2986aa6a668bce3cfb83606bb52e9d01ae66ad6c.tar.gz postgresql-2986aa6a668bce3cfb83606bb52e9d01ae66ad6c.zip | |
Add checkpoint_warning to warn of excessive checkpoints caused by too
few WAL files.
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/runtime.sgml | 14 | ||||
| -rw-r--r-- | doc/src/sgml/wal.sgml | 12 |
2 files changed, 24 insertions, 2 deletions
diff --git a/doc/src/sgml/runtime.sgml b/doc/src/sgml/runtime.sgml index 6ca8f820e34..26777ae43a8 100644 --- a/doc/src/sgml/runtime.sgml +++ b/doc/src/sgml/runtime.sgml @@ -1,5 +1,5 @@ <!-- -$Header: /cvsroot/pgsql/doc/src/sgml/runtime.sgml,v 1.154 2002/11/15 01:57:25 momjian Exp $ +$Header: /cvsroot/pgsql/doc/src/sgml/runtime.sgml,v 1.155 2002/11/15 02:44:50 momjian Exp $ --> <Chapter Id="runtime"> @@ -2081,6 +2081,18 @@ dynamic_library_path = '/usr/local/lib/postgresql:/home/my_project/lib:$libdir' </listitem> </varlistentry> + <variablelist> + <varlistentry> + <term><varname>CHECKPOINT_WARNING</varname> (<type>integer</type>)</term> + <listitem> + <para> + Send a message to the server logs if checkpoints caused by the + filling of checkpoint segment files happens more frequently than + this number of seconds. Zero turns off the warning. + </para> + </listitem> + </varlistentry> + <varlistentry> <term><varname>COMMIT_DELAY</varname> (<type>integer</type>)</term> <listitem> diff --git a/doc/src/sgml/wal.sgml b/doc/src/sgml/wal.sgml index 7f603221acc..2589ab8163b 100644 --- a/doc/src/sgml/wal.sgml +++ b/doc/src/sgml/wal.sgml @@ -1,4 +1,4 @@ -<!-- $Header: /cvsroot/pgsql/doc/src/sgml/wal.sgml,v 1.21 2002/11/02 22:23:01 tgl Exp $ --> +<!-- $Header: /cvsroot/pgsql/doc/src/sgml/wal.sgml,v 1.22 2002/11/15 02:44:54 momjian Exp $ --> <chapter id="wal"> <title>Write-Ahead Logging (<acronym>WAL</acronym>)</title> @@ -301,6 +301,16 @@ </para> <para> + Checkpoints are fairly expensive because they force all dirty kernel + buffers to disk using the operating system <literal>sync()</> call. + Busy servers may fill checkpoint segment files too quickly, + causing excessive checkpointing. If such forced checkpoints happen + more frequently than <varname>CHECKPOINT_WARNING</varname> seconds, + a message, will be output to the server logs recommending increasing + <varname>CHECKPOINT_SEGMENTS</varname>. + </para> + + <para> The <varname>COMMIT_DELAY</varname> parameter defines for how many microseconds the backend will sleep after writing a commit record to the log with <function>LogInsert</function> but before |