diff options
| -rw-r--r-- | doc/src/sgml/monitoring.sgml | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index 65da082ed9b..fd0ffbb1e08 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -5735,8 +5735,11 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i <returnvalue>bigint</returnvalue> </para> <para> - Returns the number of buffers fetched for table or index, in the current - transaction. + Returns the number of block read requests for table or index, in the + current transaction. This number minus + <function>pg_stat_get_xact_blocks_hit</function> gives the number of + kernel <function>read()</function> calls; the number of actual + physical reads is usually lower due to kernel-level buffering. </para></entry> </row> @@ -5749,8 +5752,9 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i <returnvalue>bigint</returnvalue> </para> <para> - Returns the number of buffer hits for table or index, in the current - transaction. + Returns the number of block read requests for table or index, in the + current transaction, found in cache (not triggering kernel + <function>read()</function> calls). </para></entry> </row> |