granicus.if.org Git - postgresql/blob - src/include/nodes/relation.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * relation.h--
   4  *        Definitions for internal planner nodes.
   5  *
   6  *
   7  * Copyright (c) 1994, Regents of the University of California
   8  *
   9  * $Id: relation.h,v 1.16 1999/02/08 04:29:25 momjian Exp $
  10  *
  11  *-------------------------------------------------------------------------
  12  */
  13 #ifndef RELATION_H
  14 #define RELATION_H
  15
  16 #include <nodes/parsenodes.h>
  17 #include <nodes/primnodes.h>
  18
  19 /*
  20  * Relid
  21  *              List of relation identifiers (indexes into the rangetable).
  22  */
  23
  24 typedef List *Relid;
  25
  26 /*
  27  * RelOptInfo
  28  *              Per-base-relation information
  29  *
  30  *              Parts of this data structure are specific to various scan and join
  31  *              mechanisms.  It didn't seem worth creating new node types for them.
  32  *
  33  *              relids - List of relation indentifiers
  34  *              indexed - true if the relation has secondary indices
  35  *              pages - number of pages in the relation
  36  *              tuples - number of tuples in the relation
  37  *              size - number of tuples in the relation after restrictions clauses
  38  *                         have been applied
  39  *              width - number of bytes per tuple in the relation after the
  40  *                              appropriate projections have been done
  41  *              targetlist - List of TargetList nodes
  42  *              pathlist - List of Path nodes, one for each possible method of
  43  *                                 generating the relation
  44  *              unorderedpath - a Path node generating this relation whose resulting
  45  *                                              tuples are unordered (this isn't necessarily a
  46  *                                              sequential scan path, e.g., scanning with a hash index
  47  *                                              leaves the tuples unordered)
  48  *              cheapestpath -  least expensive Path (regardless of final order)
  49  *              pruneable - flag to let the planner know whether it can prune the plan
  50  *                                      space of this RelOptInfo or not.
  51  *
  52  *       * If the relation is a (secondary) index it will have the following
  53  *              three fields:
  54  *
  55  *              classlist - List of PG_AMOPCLASS OIDs for the index
  56  *              indexkeys - List of base-relation attribute numbers that are index keys
  57  *              ordering - List of PG_OPERATOR OIDs which order the indexscan result
  58  *              relam     - the OID of the pg_am of the index
  59  *
  60  *       * The presence of the remaining fields depends on the restrictions
  61  *              and joins which the relation participates in:
  62  *
  63  *              restrictinfo - List of RestrictInfo nodes, containing info about each
  64  *                                       qualification clause in which this relation participates
  65  *              joininfo  - List of JoinInfo nodes, containing info about each join
  66  *                                      clause in which this relation participates
  67  *              innerjoin - List of Path nodes that represent indices that may be used
  68  *                                      as inner paths of nestloop joins
  69  *
  70  * NB. the last element of the arrays classlist, indexkeys and ordering
  71  *         is always 0.                                                         2/95 - ay
  72  */
  73
  74 typedef struct RelOptInfo
  75 {
  76         NodeTag         type;
  77
  78         /* all relations: */
  79         Relid           relids;
  80
  81         /* catalog statistics information */
  82         bool            indexed;
  83         int                     pages;
  84         int                     tuples;
  85         int                     size;
  86         int                     width;
  87
  88         /* materialization information */
  89         List       *targetlist;
  90         List       *pathlist;           /* Path structures */
  91         struct Path *unorderedpath;
  92         struct Path *cheapestpath;
  93         bool            pruneable;
  94
  95         /* used solely by indices: */
  96         Oid                *classlist;          /* classes of AM operators */
  97         int                *indexkeys;          /* keys over which we're indexing */
  98         Oid                     relam;                  /* OID of the access method (in pg_am) */
  99
 100         Oid                     indproc;
 101         List       *indpred;
 102
 103         /* used by various scans and joins: */
 104         Oid                *ordering;           /* OID of operators in sort order */
 105         List       *restrictinfo;       /* RestrictInfo structures */
 106         List       *joininfo;           /* JoinInfo structures */
 107         List       *innerjoin;
 108         List       *superrels;
 109 } RelOptInfo;
 110
 111 extern Var *get_expr(TargetEntry *foo);
 112
 113 typedef struct MergeOrder
 114 {
 115         NodeTag         type;
 116         Oid                     join_operator;
 117         Oid                     left_operator;
 118         Oid                     right_operator;
 119         Oid                     left_type;
 120         Oid                     right_type;
 121 } MergeOrder;
 122
 123 typedef enum OrderType
 124 {
 125         MERGE_ORDER, SORTOP_ORDER
 126 } OrderType;
 127
 128 typedef struct PathOrder
 129 {
 130         OrderType       ordtype;
 131         union
 132         {
 133                 Oid                *sortop;
 134                 MergeOrder *merge;
 135         } ord;
 136 } PathOrder;
 137
 138 typedef struct Path
 139 {
 140         NodeTag         type;
 141
 142         RelOptInfo *parent;
 143         Cost            path_cost;
 144
 145         NodeTag         pathtype;
 146
 147         PathOrder       path_order;
 148
 149         List       *keys;
 150         Cost            outerjoincost;
 151         Relid           joinid;
 152         List       *loc_restrictinfo;
 153 } Path;
 154
 155 typedef struct IndexPath
 156 {
 157         Path            path;
 158         List       *indexid;
 159         List       *indexqual;
 160         int                *indexkeys;  /* to transform heap attnos into index ones */
 161 } IndexPath;
 162
 163 typedef struct JoinPath
 164 {
 165         Path            path;
 166         List       *pathinfo;
 167         Path       *outerjoinpath;
 168         Path       *innerjoinpath;
 169 } JoinPath;
 170
 171 typedef struct MergePath
 172 {
 173         JoinPath        jpath;
 174         List       *path_mergeclauses;
 175         List       *outersortkeys;
 176         List       *innersortkeys;
 177 } MergePath;
 178
 179 typedef struct HashPath
 180 {
 181         JoinPath        jpath;
 182         List       *path_hashclauses;
 183         List       *outerhashkeys;
 184         List       *innerhashkeys;
 185 } HashPath;
 186
 187 /******
 188  * Keys
 189  ******/
 190
 191 typedef struct OrderKey
 192 {
 193         NodeTag         type;
 194         int                     attribute_number;
 195         Index           array_index;
 196 } OrderKey;
 197
 198 typedef struct JoinKey
 199 {
 200         NodeTag         type;
 201         Var                *outer;
 202         Var                *inner;
 203 } JoinKey;
 204
 205 /*******
 206  * clause info
 207  *******/
 208
 209 typedef struct RestrictInfo
 210 {
 211         NodeTag         type;
 212         Expr       *clause;                     /* should be an OP clause */
 213         Cost            selectivity;
 214         bool            notclause;
 215         List       *indexids;
 216
 217         /* mergejoin only */
 218         MergeOrder *mergejoinorder;
 219
 220         /* hashjoin only */
 221         Oid                     hashjoinoperator;
 222         Relid           restrictinfojoinid;
 223 } RestrictInfo;
 224
 225 typedef struct JoinMethod
 226 {
 227         NodeTag         type;
 228         List       *jmkeys;
 229         List       *clauses;
 230 } JoinMethod;
 231
 232 typedef struct HashInfo
 233 {
 234         JoinMethod      jmethod;
 235         Oid                     hashop;
 236 } HashInfo;
 237
 238 typedef struct MergeInfo
 239 {
 240         JoinMethod      jmethod;
 241         MergeOrder *m_ordering;
 242 } MergeInfo;
 243
 244 typedef struct JoinInfo
 245 {
 246         NodeTag         type;
 247         List       *otherrels;
 248         List       *jinfo_restrictinfo;
 249         bool            mergejoinable;
 250         bool            hashjoinable;
 251         bool            inactive;
 252 } JoinInfo;
 253
 254 typedef struct Iter
 255 {
 256         NodeTag         type;
 257         Node       *iterexpr;
 258         Oid                     itertype;               /* type of the iter expr (use for type
 259                                                                  * checking) */
 260 } Iter;
 261
 262 /*
 263 ** Stream:
 264 **       A stream represents a root-to-leaf path in a plan tree (i.e. a tree of
 265 ** JoinPaths and Paths).  The stream includes pointers to all Path nodes,
 266 ** as well as to any clauses that reside above Path nodes.      This structure
 267 ** is used to make Path nodes and clauses look similar, so that Predicate
 268 ** Migration can run.
 269 **
 270 **         pathptr -- pointer to the current path node
 271 **               cinfo -- if NULL, this stream node referes to the path node.
 272 **                                Otherwise this is a pointer to the current clause.
 273 **      clausetype -- whether cinfo is in loc_restrictinfo or pathinfo in the
 274 **                                path node
 275 **        upstream -- linked list pointer upwards
 276 **      downstream -- ditto, downwards
 277 **         groupup -- whether or not this node is in a group with the node upstream
 278 **       groupcost -- total cost of the group that node is in
 279 **        groupsel -- total selectivity of the group that node is in
 280 */
 281 typedef struct Stream *StreamPtr;
 282
 283 typedef struct Stream
 284 {
 285         NodeTag         type;
 286         Path       *pathptr;
 287         RestrictInfo *cinfo;
 288         int                *clausetype;
 289         struct Stream *upstream;
 290         struct Stream *downstream;
 291         bool            groupup;
 292         Cost            groupcost;
 293         Cost            groupsel;
 294 } Stream;
 295
 296 #endif   /* RELATION_H */