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f6d208d6e5
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
25 lines
757 B
C
25 lines
757 B
C
/*-------------------------------------------------------------------------
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*
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* nodeSamplescan.h
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*
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*
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*
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* Portions Copyright (c) 1996-2014, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* src/include/executor/nodeSamplescan.h
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*
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*-------------------------------------------------------------------------
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*/
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#ifndef NODESAMPLESCAN_H
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#define NODESAMPLESCAN_H
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#include "nodes/execnodes.h"
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extern SampleScanState *ExecInitSampleScan(SampleScan *node, EState *estate, int eflags);
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extern TupleTableSlot *ExecSampleScan(SampleScanState *node);
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extern void ExecEndSampleScan(SampleScanState *node);
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extern void ExecReScanSampleScan(SampleScanState *node);
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#endif /* NODESAMPLESCAN_H */
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