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/*-------------------------------------------------------------------------
*
* tablesample.h
* Public header file for TABLESAMPLE clause interface
*
*
* Portions Copyright (c) 1996-2015, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* src/include/access/tablesample.h
*
*-------------------------------------------------------------------------
*/
#ifndef TABLESAMPLE_H
#define TABLESAMPLE_H
#include "access/relscan.h"
#include "executor/executor.h"
typedef struct TableSampleDesc {
HeapScanDesc heapScan;
TupleDesc tupDesc; /* Mostly useful for tsmexaminetuple */
void *tsmdata; /* private method data */
/* These point to he function of the TABLESAMPLE Method. */
FmgrInfo tsminit;
FmgrInfo tsmnextblock;
FmgrInfo tsmnexttuple;
FmgrInfo tsmexaminetuple;
FmgrInfo tsmreset;
FmgrInfo tsmend;
} TableSampleDesc;
extern TableSampleDesc *tablesample_init(SampleScanState *scanstate,
TableSampleClause *tablesample);
extern HeapTuple tablesample_getnext(TableSampleDesc *desc);
extern void tablesample_reset(TableSampleDesc *desc);
extern void tablesample_end(TableSampleDesc *desc);
extern HeapTuple tablesample_source_getnext(TableSampleDesc *desc);
extern HeapTuple tablesample_source_gettup(TableSampleDesc *desc, ItemPointer tid,
bool *visible);
extern Datum tsm_system_init(PG_FUNCTION_ARGS);
extern Datum tsm_system_nextblock(PG_FUNCTION_ARGS);
extern Datum tsm_system_nexttuple(PG_FUNCTION_ARGS);
extern Datum tsm_system_end(PG_FUNCTION_ARGS);
extern Datum tsm_system_reset(PG_FUNCTION_ARGS);
extern Datum tsm_system_cost(PG_FUNCTION_ARGS);
extern Datum tsm_bernoulli_init(PG_FUNCTION_ARGS);
extern Datum tsm_bernoulli_nextblock(PG_FUNCTION_ARGS);
extern Datum tsm_bernoulli_nexttuple(PG_FUNCTION_ARGS);
extern Datum tsm_bernoulli_end(PG_FUNCTION_ARGS);
extern Datum tsm_bernoulli_reset(PG_FUNCTION_ARGS);
extern Datum tsm_bernoulli_cost(PG_FUNCTION_ARGS);
#endif
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