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| author | Fujii Masao <fujii@postgresql.org> | 2020-10-02 10:17:11 +0900 |
|---|---|---|
| committer | Fujii Masao <fujii@postgresql.org> | 2020-10-02 10:17:11 +0900 |
| commit | 8d9a935965f01b7759a8c23ff6291000b670a2bf (patch) | |
| tree | 087be8ff79f83042fe0c84771c7987bb389a25bf /src/backend/utils/adt/pgstatfuncs.c | |
| parent | 9d0bd95fa90a7243047a74e29f265296a9fc556d (diff) | |
| download | postgresql-8d9a935965f01b7759a8c23ff6291000b670a2bf.tar.gz postgresql-8d9a935965f01b7759a8c23ff6291000b670a2bf.zip | |
Add pg_stat_wal statistics view.
This view shows the statistics about WAL activity. Currently it has only
two columns: wal_buffers_full and stats_reset. wal_buffers_full column
indicates the number of times WAL data was written to the disk because
WAL buffers got full. This information is useful when tuning wal_buffers.
stats_reset column indicates the time at which these statistics were
last reset.
pg_stat_wal view is also the basic infrastructure to expose other
various statistics about WAL activity later.
Bump PGSTAT_FILE_FORMAT_ID due to the change in pgstat format.
Bump catalog version.
Author: Masahiro Ikeda
Reviewed-by: Takayuki Tsunakawa, Kyotaro Horiguchi, Amit Kapila, Fujii Masao
Discussion: https://postgr.es/m/188bd3f2d2233cf97753b5ced02bb050@oss.nttdata.com
Diffstat (limited to 'src/backend/utils/adt/pgstatfuncs.c')
| -rw-r--r-- | src/backend/utils/adt/pgstatfuncs.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c index 95738a4e34e..24e191ea30b 100644 --- a/src/backend/utils/adt/pgstatfuncs.c +++ b/src/backend/utils/adt/pgstatfuncs.c @@ -1698,6 +1698,42 @@ pg_stat_get_buf_alloc(PG_FUNCTION_ARGS) } /* + * Returns statistics of WAL activity + */ +Datum +pg_stat_get_wal(PG_FUNCTION_ARGS) +{ +#define PG_STAT_GET_WAL_COLS 2 + TupleDesc tupdesc; + Datum values[PG_STAT_GET_WAL_COLS]; + bool nulls[PG_STAT_GET_WAL_COLS]; + PgStat_WalStats *wal_stats; + + /* Initialise values and NULL flags arrays */ + MemSet(values, 0, sizeof(values)); + MemSet(nulls, 0, sizeof(nulls)); + + /* Initialise attributes information in the tuple descriptor */ + tupdesc = CreateTemplateTupleDesc(PG_STAT_GET_WAL_COLS); + TupleDescInitEntry(tupdesc, (AttrNumber) 1, "wal_buffers_full", + INT8OID, -1, 0); + TupleDescInitEntry(tupdesc, (AttrNumber) 2, "stats_reset", + TIMESTAMPTZOID, -1, 0); + + BlessTupleDesc(tupdesc); + + /* Get statistics about WAL activity */ + wal_stats = pgstat_fetch_stat_wal(); + + /* Fill values and NULLs */ + values[0] = Int64GetDatum(wal_stats->wal_buffers_full); + values[1] = TimestampTzGetDatum(wal_stats->stat_reset_timestamp); + + /* Returns the record as Datum */ + PG_RETURN_DATUM(HeapTupleGetDatum(heap_form_tuple(tupdesc, values, nulls))); +} + +/* * Returns statistics of SLRU caches. */ Datum |