diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/monitoring.sgml | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index f5cf163c8c6..aeb694d4a86 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -2603,9 +2603,9 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i </para> <para> Number of transactions spilled to disk after the memory used by - logical decoding exceeds <literal>logical_decoding_work_mem</literal>. The - counter gets incremented both for toplevel transactions and - subtransactions. + logical decoding of changes from WAL for this slot exceeds + <literal>logical_decoding_work_mem</literal>. The counter gets + incremented both for toplevel transactions and subtransactions. </para></entry> </row> @@ -2614,7 +2614,8 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i <structfield>spill_count</structfield> <type>bigint</type> </para> <para> - Number of times transactions were spilled to disk. Transactions + Number of times transactions were spilled to disk while performing + decoding of changes from WAL for this slot. Transactions may get spilled repeatedly, and this counter gets incremented on every such invocation. </para></entry> @@ -2625,7 +2626,10 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i <structfield>spill_bytes</structfield> <type>bigint</type> </para> <para> - Amount of decoded transaction data spilled to disk. + Amount of decoded transaction data spilled to disk while performing + decoding of changes from WAL for this slot. This and other spill + counters can be used to gauge the I/O occurred during logical decoding + and accordingly can tune <literal>logical_decoding_work_mem</literal>. </para></entry> </row> |