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 1.1 1996/08/27 21:50:25 scrappy Exp $
  11  *
  12  *-------------------------------------------------------------------------
  13  */
  14 #ifndef STRAT_H
  15 #define STRAT_H
  16
  17 #include "postgres.h"
  18 #include "access/attnum.h"
  19 #include "access/skey.h"
  20
  21 typedef uint16  StrategyNumber;
  22
  23 #define InvalidStrategy 0
  24
  25 typedef struct StrategyTransformMapData {
  26     StrategyNumber      strategy[1];    /* VARIABLE LENGTH ARRAY */
  27 } StrategyTransformMapData;     /* VARIABLE LENGTH STRUCTURE */
  28
  29 typedef StrategyTransformMapData        *StrategyTransformMap;
  30
  31 typedef struct StrategyOperatorData {
  32     StrategyNumber      strategy;
  33     bits16              flags;          /* scan qualification flags h/skey.h */
  34 } StrategyOperatorData;
  35
  36 typedef StrategyOperatorData    *StrategyOperator;
  37
  38 typedef struct StrategyTermData {       /* conjunctive term */
  39     uint16                      degree;
  40     StrategyOperatorData        operatorData[1];        /* VARIABLE LENGTH */
  41 } StrategyTermData;     /* VARIABLE LENGTH STRUCTURE */
  42
  43 typedef StrategyTermData        *StrategyTerm;
  44
  45 typedef struct StrategyExpressionData { /* disjunctive normal form */
  46     StrategyTerm        term[1];        /* VARIABLE LENGTH ARRAY */
  47 } StrategyExpressionData;       /* VARIABLE LENGTH STRUCTURE */
  48
  49 typedef StrategyExpressionData  *StrategyExpression;
  50
  51 typedef struct StrategyEvaluationData {
  52     StrategyNumber              maxStrategy;
  53     StrategyTransformMap        negateTransform;
  54     StrategyTransformMap        commuteTransform;
  55     StrategyTransformMap        negateCommuteTransform;
  56     StrategyExpression  expression[12]; /* XXX VARIABLE LENGTH */
  57 } StrategyEvaluationData;       /* VARIABLE LENGTH STRUCTURE */
  58
  59 typedef StrategyEvaluationData  *StrategyEvaluation;
  60
  61 /*
  62  * StrategyTransformMapIsValid --
  63  *      Returns true iff strategy transformation map is valid.
  64  */
  65 #define StrategyTransformMapIsValid(transform) PointerIsValid(transform)
  66
  67
  68 #ifndef CorrectStrategies               /* XXX this should be removable */
  69 #define AMStrategies(foo)       12
  70 #else   /* !defined(CorrectStrategies) */
  71 #define AMStrategies(foo)       (foo)
  72 #endif  /* !defined(CorrectStrategies) */
  73
  74 typedef struct StrategyMapData {
  75         ScanKeyData             entry[1];       /* VARIABLE LENGTH ARRAY */
  76 } StrategyMapData;      /* VARIABLE LENGTH STRUCTURE */
  77
  78 typedef StrategyMapData *StrategyMap;
  79
  80 typedef struct IndexStrategyData {
  81         StrategyMapData strategyMapData[1];     /* VARIABLE LENGTH ARRAY */
  82 } IndexStrategyData;    /* VARIABLE LENGTH STRUCTURE */
  83
  84 typedef IndexStrategyData       *IndexStrategy;
  85
  86 #endif /*STRAT_H */