41 lines
1.0 KiB
C
41 lines
1.0 KiB
C
/*-------------------------------------------------------------------------
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*
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* tablesample.c
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* Support functions for TABLESAMPLE feature
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*
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* Portions Copyright (c) 1996-2015, 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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*
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* IDENTIFICATION
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* src/backend/access/tablesample/tablesample.c
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*
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* -------------------------------------------------------------------------
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*/
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#include "postgres.h"
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#include "access/tsmapi.h"
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/*
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* GetTsmRoutine --- get a TsmRoutine struct by invoking the handler.
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*
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* This is a convenience routine that's just meant to check for errors.
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*/
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TsmRoutine *
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GetTsmRoutine(Oid tsmhandler)
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{
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Datum datum;
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TsmRoutine *routine;
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datum = OidFunctionCall1(tsmhandler, PointerGetDatum(NULL));
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routine = (TsmRoutine *) DatumGetPointer(datum);
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if (routine == NULL || !IsA(routine, TsmRoutine))
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elog(ERROR, "tablesample handler function %u did not return a TsmRoutine struct",
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tsmhandler);
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return routine;
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}
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