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<chapter id="monitoring">

<title>Monitoring Database Activity</title>

<entry><type>bigint</type></entry>

<entry>

The number of times the bgwriter has started timed checkpoints

(because the <varname>checkpoint_timeout</varname> time has expired).

(because the <varname>checkpoint_timeout</varname> time has expired)

</entry>

</row>

<row>

<entry><literal><function>pg_stat_get_bgwriter_requested_checkpoints</function>()</literal></entry>

<entry><type>bigint</type></entry>

<entry>

The number of times the bgwriter has started checkpoints based on

requests from backends because the <varname>checkpoint_segments</varname>

has been exceeded or because the CHECKPOINT command has been issued.

The number of times the bgwriter has started checkpoints based

on requests from backends because the <varname>checkpoint_segments</varname>

has been exceeded or because the <command>CHECKPOINT</command>

command has been issued

</entry>

</row>

<row>

<entry><literal><function>pg_stat_get_bgwriter_buf_written_checkpoints</function>()</literal></entry>

<entry><type>bigint</type></entry>

<entry>

The number of buffers written by the bgwriter during checkpoints.

The number of buffers written by the bgwriter during checkpoints

</entry>

</row>

<entry><type>bigint</type></entry>

<entry>

The number of buffers written by the bgwriter when performing a

LRU scan of the buffer cache.

LRU scan of the buffer cache

</entry>

</row>

<entry><type>bigint</type></entry>

<entry>

The number of buffers written by the bgwriter when performing a

scan of all the buffer cache.

scan of all the buffer cache

</entry>

</row>

<entry>

The number of times the bgwriter has stopped its LRU round because

it has written more buffers than specified in the

<varname>bgwriter_lru_maxpages</varname> parameter.

<varname>bgwriter_lru_maxpages</varname> parameter

</entry>

</row>

<entry>

The number of times the bgwriter has stopped its all-buffer round

because it has written more buffers than specified in the

<varname>bgwriter_all_maxpages</varname> parameter.

<varname>bgwriter_all_maxpages</varname> parameter

</entry>

</row>