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 1.5 1997/09/07 04:56:14 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                                                                                                  * STRUCTURE */
  29
  30 typedef StrategyTransformMapData *StrategyTransformMap;
  31
  32 typedef struct StrategyOperatorData
  33 {
  34         StrategyNumber  strategy;
  35         bits16                  flags;          /* scan qualification flags h/skey.h */
  36 }                               StrategyOperatorData;
  37
  38 typedef StrategyOperatorData *StrategyOperator;
  39
  40 typedef struct StrategyTermData
  41 {                                                               /* conjunctive term */
  42         uint16                  degree;
  43         StrategyOperatorData operatorData[1];           /* VARIABLE LENGTH */
  44 }                               StrategyTermData;               /* VARIABLE LENGTH STRUCTURE */
  45
  46 typedef StrategyTermData *StrategyTerm;
  47
  48 typedef struct StrategyExpressionData
  49 {                                                               /* disjunctive normal form */
  50         StrategyTerm    term[1];        /* VARIABLE LENGTH ARRAY */
  51 }                               StrategyExpressionData; /* VARIABLE LENGTH STRUCTURE */
  52
  53 typedef StrategyExpressionData *StrategyExpression;
  54
  55 typedef struct StrategyEvaluationData
  56 {
  57         StrategyNumber  maxStrategy;
  58         StrategyTransformMap negateTransform;
  59         StrategyTransformMap commuteTransform;
  60         StrategyTransformMap negateCommuteTransform;
  61         StrategyExpression expression[12];      /* XXX VARIABLE LENGTH */
  62 }                               StrategyEvaluationData; /* VARIABLE LENGTH STRUCTURE */
  63
  64 typedef StrategyEvaluationData *StrategyEvaluation;
  65
  66 /*
  67  * StrategyTransformMapIsValid --
  68  *              Returns true iff strategy transformation map is valid.
  69  */
  70 #define StrategyTransformMapIsValid(transform) PointerIsValid(transform)
  71
  72
  73 #ifndef CorrectStrategies               /* XXX this should be removable */
  74 #define AMStrategies(foo)               12
  75 #else                                                   /* !defined(CorrectStrategies) */
  76 #define AMStrategies(foo)               (foo)
  77 #endif                                                  /* !defined(CorrectStrategies) */
  78
  79 typedef struct StrategyMapData
  80 {
  81         ScanKeyData             entry[1];       /* VARIABLE LENGTH ARRAY */
  82 }                               StrategyMapData;/* VARIABLE LENGTH STRUCTURE */
  83
  84 typedef StrategyMapData *StrategyMap;
  85
  86 typedef struct IndexStrategyData
  87 {
  88         StrategyMapData strategyMapData[1]; /* VARIABLE LENGTH ARRAY */
  89 }                               IndexStrategyData;              /* VARIABLE LENGTH STRUCTURE */
  90
  91 typedef IndexStrategyData *IndexStrategy;
  92
  93 #endif                                                  /* STRAT_H */