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  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
   9  * Portions Copyright (c) 1994, Regents of the University of California
  10  *
  11  * $Id: strat.h,v 1.27 2003/08/04 02:40:10 momjian Exp $
  12  *
  13  *-------------------------------------------------------------------------
  14  */
  15 #ifndef STRAT_H
  16 #define STRAT_H
  17
  18 #include "access/skey.h"
  19
  20
  21 typedef uint16 StrategyNumber;
  22
  23 #define InvalidStrategy 0
  24
  25 typedef struct StrategyTransformMapData
  26 {
  27         StrategyNumber strategy[1]; /* VARIABLE LENGTH ARRAY */
  28 } StrategyTransformMapData;             /* VARIABLE LENGTH STRUCTURE */
  29
  30 typedef StrategyTransformMapData *StrategyTransformMap;
  31
  32 typedef struct StrategyOperatorData
  33 {
  34         StrategyNumber strategy;
  35         bits16          flags;                  /* scan qualification flags, see 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 ARRAY */
  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         /* each of these must point to an array of maxStrategy elements: */
  59         StrategyTransformMap negateTransform;
  60         StrategyTransformMap commuteTransform;
  61         StrategyTransformMap negateCommuteTransform;
  62         StrategyExpression *expression;
  63 } StrategyEvaluationData;
  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 #define AMStrategies(foo)               (foo)
  75
  76 typedef struct StrategyMapData
  77 {
  78         ScanKeyData entry[1];           /* VARIABLE LENGTH ARRAY */
  79 } StrategyMapData;                              /* VARIABLE LENGTH STRUCTURE */
  80
  81 typedef StrategyMapData *StrategyMap;
  82
  83 typedef struct IndexStrategyData
  84 {
  85         StrategyMapData strategyMapData[1]; /* VARIABLE LENGTH ARRAY */
  86 } IndexStrategyData;                    /* VARIABLE LENGTH STRUCTURE */
  87
  88 typedef IndexStrategyData *IndexStrategy;
  89
  90 #endif   /* STRAT_H */