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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2007-06-08 18:23:53 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2007-06-08 18:23:53 +0000 |
| commit | a04a423599b347325f9a73dfb2d533b24e1cbab3 (patch) | |
| tree | 5aeb620900a705222eb202c7b4b1d33266d1c190 /src/backend/storage/buffer/freelist.c | |
| parent | 6d6d14b6d52f7a709fba8fd23244a7de014f2048 (diff) | |
| download | postgresql-a04a423599b347325f9a73dfb2d533b24e1cbab3.tar.gz postgresql-a04a423599b347325f9a73dfb2d533b24e1cbab3.zip | |
Arrange for large sequential scans to synchronize with each other, so that
when multiple backends are scanning the same relation concurrently, each page
is (ideally) read only once.
Jeff Davis, with review by Heikki and Tom.
Diffstat (limited to 'src/backend/storage/buffer/freelist.c')
| -rw-r--r-- | src/backend/storage/buffer/freelist.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index d8eec0f8231..a3e2c7c4422 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -9,7 +9,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/storage/buffer/freelist.c,v 1.59 2007/05/30 20:11:59 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/storage/buffer/freelist.c,v 1.60 2007/06/08 18:23:52 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -340,6 +340,9 @@ GetAccessStrategy(BufferAccessStrategyType btype) * Select ring size to use. See buffer/README for rationales. * (Currently all cases are the same size, but keep this code * structure for flexibility.) + * + * Note: if you change the ring size for BAS_BULKREAD, see also + * SYNC_SCAN_REPORT_INTERVAL in access/heap/syncscan.c. */ switch (btype) { |