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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/nodes/execnodes.h | |
| parent | 11a83bbedd73800db70f6f2af5a8eb10d15d39d7 (diff) | |
| download | postgresql-f6d208d6e51810c73f0e02c477984a6b44627f11.tar.gz | |
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/nodes/execnodes.h')
| -rw-r--r-- | src/include/nodes/execnodes.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h index fcfe1107f9..972368019a 100644 --- a/src/include/nodes/execnodes.h +++ b/src/include/nodes/execnodes.h @@ -1238,6 +1238,15 @@ typedef struct ScanState typedef ScanState SeqScanState; /* + * SampleScan + */ +typedef struct SampleScanState +{ + ScanState ss; + struct TableSampleDesc *tsdesc; +} SampleScanState; + +/* * These structs store information about index quals that don't have simple * constant right-hand sides. See comments for ExecIndexBuildScanKeys() * for discussion. |