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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2007-09-25 20:03:38 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2007-09-25 20:03:38 +0000 |
| commit | 6f5c38dcd0dfb391bcbaa683a96f4a62c574d95a (patch) | |
| tree | 720d4cd3b589bdff97825ed56cc5e1de706bcd87 /src/backend/utils/adt/pgstatfuncs.c | |
| parent | 588901df84588981aabf40df3287219405ec443b (diff) | |
| download | postgresql-6f5c38dcd0dfb391bcbaa683a96f4a62c574d95a.tar.gz postgresql-6f5c38dcd0dfb391bcbaa683a96f4a62c574d95a.zip | |
Just-in-time background writing strategy. This code avoids re-scanning
buffers that cannot possibly need to be cleaned, and estimates how many
buffers it should try to clean based on moving averages of recent allocation
requests and density of reusable buffers. The patch also adds a couple
more columns to pg_stat_bgwriter to help measure the effectiveness of the
bgwriter.
Greg Smith, building on his own work and ideas from several other people,
in particular a much older patch from Itagaki Takahiro.
Diffstat (limited to 'src/backend/utils/adt/pgstatfuncs.c')
| -rw-r--r-- | src/backend/utils/adt/pgstatfuncs.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c index 954e174bb71..f162381745c 100644 --- a/src/backend/utils/adt/pgstatfuncs.c +++ b/src/backend/utils/adt/pgstatfuncs.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/utils/adt/pgstatfuncs.c,v 1.45 2007/09/20 17:56:31 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/utils/adt/pgstatfuncs.c,v 1.46 2007/09/25 20:03:38 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -67,6 +67,8 @@ extern Datum pg_stat_get_bgwriter_requested_checkpoints(PG_FUNCTION_ARGS); extern Datum pg_stat_get_bgwriter_buf_written_checkpoints(PG_FUNCTION_ARGS); extern Datum pg_stat_get_bgwriter_buf_written_clean(PG_FUNCTION_ARGS); extern Datum pg_stat_get_bgwriter_maxwritten_clean(PG_FUNCTION_ARGS); +extern Datum pg_stat_get_buf_written_backend(PG_FUNCTION_ARGS); +extern Datum pg_stat_get_buf_alloc(PG_FUNCTION_ARGS); extern Datum pg_stat_clear_snapshot(PG_FUNCTION_ARGS); extern Datum pg_stat_reset(PG_FUNCTION_ARGS); @@ -813,6 +815,18 @@ pg_stat_get_bgwriter_maxwritten_clean(PG_FUNCTION_ARGS) PG_RETURN_INT64(pgstat_fetch_global()->maxwritten_clean); } +Datum +pg_stat_get_buf_written_backend(PG_FUNCTION_ARGS) +{ + PG_RETURN_INT64(pgstat_fetch_global()->buf_written_backend); +} + +Datum +pg_stat_get_buf_alloc(PG_FUNCTION_ARGS) +{ + PG_RETURN_INT64(pgstat_fetch_global()->buf_alloc); +} + /* Discard the active statistics snapshot */ Datum |