pg_stat_statements: Add wal_buffers_full

wal_buffers_full tracks the number of times WAL buffers become full,
giving hints to be able to tune the GUC wal_buffers.

Up to now, this information was only available in pg_stat_wal.  With
this field available in WalUsage since eaf502747bac, exposing it in
pg_stat_statements is straight-forward, and it offers more granularity
at query level.

pg_stat_statements does not need a version bump as one has been done in
commit cf54a2c00254 for this development cycle.

Author: Bertrand Drouvot
Reviewed-by: Ilia Evdokimov
Discussion: https://postgr.es/m/Z6SOha5YFFgvpwQY@ip-10-97-1-34.eu-west-3.compute.internal
This commit is contained in:
Michael Paquier 2025-02-17 13:55:17 +09:00
parent eaf502747b
commit ce5bcc4a9f
4 changed files with 19 additions and 2 deletions

View File

@ -385,6 +385,7 @@ AlTER EXTENSION pg_stat_statements UPDATE TO '1.12';
wal_records | bigint | | |
wal_fpi | bigint | | |
wal_bytes | numeric | | |
wal_buffers_full | bigint | | |
jit_functions | bigint | | |
jit_generation_time | double precision | | |
jit_inlining_count | bigint | | |

View File

@ -50,6 +50,7 @@ CREATE FUNCTION pg_stat_statements(IN showtext boolean,
OUT wal_records int8,
OUT wal_fpi int8,
OUT wal_bytes numeric,
OUT wal_buffers_full int8,
OUT jit_functions int8,
OUT jit_generation_time float8,
OUT jit_inlining_count int8,

View File

@ -187,6 +187,7 @@ typedef struct Counters
int64 wal_records; /* # of WAL records generated */
int64 wal_fpi; /* # of WAL full page images generated */
uint64 wal_bytes; /* total amount of WAL generated in bytes */
int64 wal_buffers_full; /* # of times the WAL buffers became full */
int64 jit_functions; /* total number of JIT functions emitted */
double jit_generation_time; /* total time to generate jit code */
int64 jit_inlining_count; /* number of times inlining time has been
@ -1465,6 +1466,7 @@ pgss_store(const char *query, uint64 queryId,
entry->counters.wal_records += walusage->wal_records;
entry->counters.wal_fpi += walusage->wal_fpi;
entry->counters.wal_bytes += walusage->wal_bytes;
entry->counters.wal_buffers_full += walusage->wal_buffers_full;
if (jitusage)
{
entry->counters.jit_functions += jitusage->created_functions;
@ -1557,8 +1559,8 @@ pg_stat_statements_reset(PG_FUNCTION_ARGS)
#define PG_STAT_STATEMENTS_COLS_V1_9 33
#define PG_STAT_STATEMENTS_COLS_V1_10 43
#define PG_STAT_STATEMENTS_COLS_V1_11 49
#define PG_STAT_STATEMENTS_COLS_V1_12 51
#define PG_STAT_STATEMENTS_COLS 51 /* maximum of above */
#define PG_STAT_STATEMENTS_COLS_V1_12 52
#define PG_STAT_STATEMENTS_COLS 52 /* maximum of above */
/*
* Retrieve statement statistics.
@ -1955,6 +1957,10 @@ pg_stat_statements_internal(FunctionCallInfo fcinfo,
Int32GetDatum(-1));
values[i++] = wal_bytes;
}
if (api_version >= PGSS_V1_12)
{
values[i++] = Int64GetDatumFast(tmp.wal_buffers_full);
}
if (api_version >= PGSS_V1_10)
{
values[i++] = Int64GetDatumFast(tmp.jit_functions);

View File

@ -436,6 +436,15 @@
</para></entry>
</row>
<row>
<entry role="catalog_table_entry"><para role="column_definition">
<structfield>wal_buffers_full</structfield> <type>bigint</type>
</para>
<para>
Number of times the WAL buffers became full
</para></entry>
</row>
<row>
<entry role="catalog_table_entry"><para role="column_definition">
<structfield>jit_functions</structfield> <type>bigint</type>