granicus.if.org Git - postgresql/blob - src/include/utils/tqual.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * tqual.h--
   4  *        POSTGRES time qualification definitions.
   5  *
   6  *
   7  * Copyright (c) 1994, Regents of the University of California
   8  *
   9  * $Id: tqual.h,v 1.7 1997/09/07 05:03:03 momjian Exp $
  10  *
  11  * NOTE
  12  *        It may be desirable to allow time qualifications to indicate
  13  *        relative times.
  14  *
  15  *-------------------------------------------------------------------------
  16  */
  17 #ifndef TQUAL_H
  18 #define TQUAL_H
  19
  20 #include <access/htup.h>
  21
  22 typedef struct TimeQualSpace
  23 {
  24         char                    data[12];
  25 }                               TimeQualSpace;
  26
  27 typedef Pointer TimeQual;
  28
  29 /* Tuples valid as of StartTransactionCommand */
  30 #define NowTimeQual             ((TimeQual) NULL)
  31
  32 /* As above, plus updates in this command */
  33 extern TimeQual SelfTimeQual;
  34
  35 extern void             setheapoverride(bool on);
  36 extern bool             heapisoverride(void);
  37
  38 extern TimeQual TimeFormSnapshotTimeQual(AbsoluteTime time);
  39 extern TimeQual
  40 TimeFormRangedTimeQual(AbsoluteTime startTime,
  41                                            AbsoluteTime endTime);
  42 extern bool             HeapTupleSatisfiesTimeQual(HeapTuple tuple, TimeQual qual);
  43
  44
  45 #endif                                                  /* TQUAL_H */