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| author | Simon Riggs <simon@2ndQuadrant.com> | 2015-05-15 14:37:10 -0400 |
|---|---|---|
| committer | Simon Riggs <simon@2ndQuadrant.com> | 2015-05-15 14:37:10 -0400 |
| commit | f6d208d6e51810c73f0e02c477984a6b44627f11 (patch) | |
| tree | 99d540d0b7bda73ff60479f15444f554403d4679 /src/include/access/heapam.h | |
| parent | 11a83bbedd73800db70f6f2af5a8eb10d15d39d7 (diff) | |
| download | postgresql-f6d208d6e51810c73f0e02c477984a6b44627f11.tar.gz postgresql-f6d208d6e51810c73f0e02c477984a6b44627f11.zip | |
TABLESAMPLE, SQL Standard and extensible
Add a TABLESAMPLE clause to SELECT statements that allows
user to specify random BERNOULLI sampling or block level
SYSTEM sampling. Implementation allows for extensible
sampling functions to be written, using a standard API.
Basic version follows SQLStandard exactly. Usable
concrete use cases for the sampling API follow in later
commits.
Petr Jelinek
Reviewed by Michael Paquier and Simon Riggs
Diffstat (limited to 'src/include/access/heapam.h')
| -rw-r--r-- | src/include/access/heapam.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/src/include/access/heapam.h b/src/include/access/heapam.h index 49c8ca4d66e..eec7c95b218 100644 --- a/src/include/access/heapam.h +++ b/src/include/access/heapam.h @@ -114,8 +114,12 @@ extern HeapScanDesc heap_beginscan_strat(Relation relation, Snapshot snapshot, bool allow_strat, bool allow_sync); extern HeapScanDesc heap_beginscan_bm(Relation relation, Snapshot snapshot, int nkeys, ScanKey key); +extern HeapScanDesc heap_beginscan_sampling(Relation relation, + Snapshot snapshot, int nkeys, ScanKey key, + bool allow_strat, bool allow_pagemode); extern void heap_setscanlimits(HeapScanDesc scan, BlockNumber startBlk, BlockNumber endBlk); +extern void heapgetpage(HeapScanDesc scan, BlockNumber page); extern void heap_rescan(HeapScanDesc scan, ScanKey key); extern void heap_endscan(HeapScanDesc scan); extern HeapTuple heap_getnext(HeapScanDesc scan, ScanDirection direction); |