granicus.if.org Git - postgresql/blob - src/include/access/strat.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * strat.h--
   4  *        index strategy type definitions
   5  *        (separated out from original istrat.h to avoid circular refs)
   6  *
   7  *
   8  * Copyright (c) 1994, Regents of the University of California
   9  *
  10  * $Id: strat.h,v 1.6 1997/09/08 02:34:27 momjian Exp $
  11  *
  12  *-------------------------------------------------------------------------
  13  */
  14 #ifndef STRAT_H
  15 #define STRAT_H
  16
  17 #include <access/skey.h>
  18
  19 typedef uint16 StrategyNumber;
  20
  21 #define InvalidStrategy 0
  22
  23 typedef struct StrategyTransformMapData
  24 {
  25         StrategyNumber strategy[1]; /* VARIABLE LENGTH ARRAY */
  26 }                       StrategyTransformMapData;       /* VARIABLE LENGTH
  27
  28                                                                                  *
  29                                                                                  * STRUCTURE */
  30
  31 typedef StrategyTransformMapData *StrategyTransformMap;
  32
  33 typedef struct StrategyOperatorData
  34 {
  35         StrategyNumber strategy;
  36         bits16          flags;                  /* scan qualification flags h/skey.h */
  37 }                       StrategyOperatorData;
  38
  39 typedef StrategyOperatorData *StrategyOperator;
  40
  41 typedef struct StrategyTermData
  42 {                                                               /* conjunctive term */
  43         uint16          degree;
  44         StrategyOperatorData operatorData[1];           /* VARIABLE LENGTH */
  45 }                       StrategyTermData;       /* VARIABLE LENGTH STRUCTURE */
  46
  47 typedef StrategyTermData *StrategyTerm;
  48
  49 typedef struct StrategyExpressionData
  50 {                                                               /* disjunctive normal form */
  51         StrategyTerm term[1];           /* VARIABLE LENGTH ARRAY */
  52 }                       StrategyExpressionData;         /* VARIABLE LENGTH STRUCTURE */
  53
  54 typedef StrategyExpressionData *StrategyExpression;
  55
  56 typedef struct StrategyEvaluationData
  57 {
  58         StrategyNumber maxStrategy;
  59         StrategyTransformMap negateTransform;
  60         StrategyTransformMap commuteTransform;
  61         StrategyTransformMap negateCommuteTransform;
  62         StrategyExpression expression[12];      /* XXX VARIABLE LENGTH */
  63 }                       StrategyEvaluationData;         /* VARIABLE LENGTH STRUCTURE */
  64
  65 typedef StrategyEvaluationData *StrategyEvaluation;
  66
  67 /*
  68  * StrategyTransformMapIsValid --
  69  *              Returns true iff strategy transformation map is valid.
  70  */
  71 #define StrategyTransformMapIsValid(transform) PointerIsValid(transform)
  72
  73
  74 #ifndef CorrectStrategies               /* XXX this should be removable */
  75 #define AMStrategies(foo)               12
  76 #else                                                   /* !defined(CorrectStrategies) */
  77 #define AMStrategies(foo)               (foo)
  78 #endif                                                  /* !defined(CorrectStrategies) */
  79
  80 typedef struct StrategyMapData
  81 {
  82         ScanKeyData entry[1];           /* VARIABLE LENGTH ARRAY */
  83 }                       StrategyMapData;        /* VARIABLE LENGTH STRUCTURE */
  84
  85 typedef StrategyMapData *StrategyMap;
  86
  87 typedef struct IndexStrategyData
  88 {
  89         StrategyMapData strategyMapData[1]; /* VARIABLE LENGTH ARRAY */
  90 }                       IndexStrategyData;      /* VARIABLE LENGTH STRUCTURE */
  91
  92 typedef IndexStrategyData *IndexStrategy;
  93
  94 #endif                                                  /* STRAT_H */