diff options
Diffstat (limited to 'src/include/nodes/relation.h')
| -rw-r--r-- | src/include/nodes/relation.h | 89 |
1 files changed, 51 insertions, 38 deletions
diff --git a/src/include/nodes/relation.h b/src/include/nodes/relation.h index f01877a9e89..b7d65131066 100644 --- a/src/include/nodes/relation.h +++ b/src/include/nodes/relation.h @@ -7,7 +7,7 @@ * Portions Copyright (c) 1996-2000, PostgreSQL, Inc * Portions Copyright (c) 1994, Regents of the University of California * - * $Id: relation.h,v 1.46 2000/03/22 22:08:29 tgl Exp $ + * $Id: relation.h,v 1.47 2000/04/12 17:16:40 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -30,7 +30,10 @@ typedef List *Relids; * When looking for a "cheapest path", this enum specifies whether we want * cheapest startup cost or cheapest total cost. */ -typedef enum CostSelector { STARTUP_COST, TOTAL_COST } CostSelector; +typedef enum CostSelector +{ + STARTUP_COST, TOTAL_COST +} CostSelector; /* * RelOptInfo @@ -82,7 +85,7 @@ typedef enum CostSelector { STARTUP_COST, TOTAL_COST } CostSelector; * (For example, in a 3-base-rel join, a clause relating rels 1 and 2 must be * treated as a restrictclause if we join {1} and {2 3} to make {1 2 3}; but * if we join {1 2} and {3} then that clause will be a restrictclause in {1 2} - * and should not be processed again at the level of {1 2 3}.) Therefore, + * and should not be processed again at the level of {1 2 3}.) Therefore, * the restrictinfo list in the join case appears in individual JoinPaths * (field joinrestrictinfo), not in the parent relation. But it's OK for * the RelOptInfo to store the joininfo lists, because those are the same @@ -98,7 +101,8 @@ typedef struct RelOptInfo NodeTag type; /* all relations included in this RelOptInfo */ - Relids relids; /* integer list of base relids (RT indexes) */ + Relids relids; /* integer list of base relids (RT + * indexes) */ /* size estimates generated by planner */ double rows; /* estimated number of result tuples */ @@ -117,11 +121,14 @@ typedef struct RelOptInfo double tuples; /* used by various scans and joins: */ - List *baserestrictinfo; /* RestrictInfo structures (if base rel) */ - Cost baserestrictcost; /* cost of evaluating the above */ + List *baserestrictinfo; /* RestrictInfo structures (if + * base rel) */ + Cost baserestrictcost; /* cost of evaluating the above */ List *joininfo; /* JoinInfo structures */ List *innerjoin; /* potential indexscans for nestloop joins */ - /* innerjoin indexscans are not in the main pathlist because they are + + /* + * innerjoin indexscans are not in the main pathlist because they are * not usable except in specific join contexts; we have to test before * seeing whether they can be used. */ @@ -143,8 +150,8 @@ typedef struct RelOptInfo * ordering - List of PG_OPERATOR OIDs which order the indexscan result * relam - the OID of the pg_am of the index * amcostestimate - OID of the relam's cost estimator - * indproc - OID of the function if a functional index, else 0 - * indpred - index predicate if a partial index, else NULL + * indproc - OID of the function if a functional index, else 0 + * indpred - index predicate if a partial index, else NULL * lossy - true if index is lossy (may return non-matching tuples) * * NB. the last element of the arrays classlist, indexkeys and ordering @@ -167,7 +174,7 @@ typedef struct IndexOptInfo Oid *ordering; /* OIDs of sort operators for each key */ Oid relam; /* OID of the access method (in pg_am) */ - RegProcedure amcostestimate; /* OID of the access method's cost fcn */ + RegProcedure amcostestimate;/* OID of the access method's cost fcn */ Oid indproc; /* if a functional index */ List *indpred; /* if a partial index */ @@ -178,11 +185,11 @@ typedef struct IndexOptInfo * PathKeys * * The sort ordering of a path is represented by a list of sublists of - * PathKeyItem nodes. An empty list implies no known ordering. Otherwise + * PathKeyItem nodes. An empty list implies no known ordering. Otherwise * the first sublist represents the primary sort key, the second the - * first secondary sort key, etc. Each sublist contains one or more + * first secondary sort key, etc. Each sublist contains one or more * PathKeyItem nodes, each of which can be taken as the attribute that - * appears at that sort position. (See the top of optimizer/path/pathkeys.c + * appears at that sort position. (See the top of optimizer/path/pathkeys.c * for more information.) */ @@ -192,11 +199,12 @@ typedef struct PathKeyItem Node *key; /* the item that is ordered */ Oid sortop; /* the ordering operator ('<' op) */ + /* - * key typically points to a Var node, ie a relation attribute, - * but it can also point to a Func clause representing the value - * indexed by a functional index. Someday we might allow arbitrary - * expressions as path keys, so don't assume more than you must. + * key typically points to a Var node, ie a relation attribute, but it + * can also point to a Func clause representing the value indexed by a + * functional index. Someday we might allow arbitrary expressions as + * path keys, so don't assume more than you must. */ } PathKeyItem; @@ -212,8 +220,10 @@ typedef struct Path RelOptInfo *parent; /* the relation this path can build */ /* estimated execution costs for path (see costsize.c for more info) */ - Cost startup_cost; /* cost expended before fetching any tuples */ - Cost total_cost; /* total cost (assuming all tuples fetched) */ + Cost startup_cost; /* cost expended before fetching any + * tuples */ + Cost total_cost; /* total cost (assuming all tuples + * fetched) */ NodeTag pathtype; /* tag identifying scan/join method */ /* XXX why is pathtype separate from the NodeTag? */ @@ -223,10 +233,10 @@ typedef struct Path } Path; /*---------- - * IndexPath represents an index scan. Although an indexscan can only read + * IndexPath represents an index scan. Although an indexscan can only read * a single relation, it can scan it more than once, potentially using a * different index during each scan. The result is the union (OR) of all the - * tuples matched during any scan. (The executor is smart enough not to return + * tuples matched during any scan. (The executor is smart enough not to return * the same tuple more than once, even if it is matched in multiple scans.) * * 'indexid' is a list of index relation OIDs, one per scan to be performed. @@ -272,10 +282,10 @@ typedef struct IndexPath typedef struct TidPath { - Path path; - List *tideval; - Relids unjoined_relids; /* some rels not yet part of my Path */ -} TidPath; + Path path; + List *tideval; + Relids unjoined_relids;/* some rels not yet part of my Path */ +} TidPath; /* * All join-type paths share these fields. @@ -287,8 +297,10 @@ typedef struct JoinPath Path *outerjoinpath; /* path for the outer side of the join */ Path *innerjoinpath; /* path for the inner side of the join */ - List *joinrestrictinfo; /* RestrictInfos to apply to join */ - /* See the notes for RelOptInfo to understand why joinrestrictinfo is + List *joinrestrictinfo; /* RestrictInfos to apply to join */ + + /* + * See the notes for RelOptInfo to understand why joinrestrictinfo is * needed in JoinPath, and can't be merged into the parent RelOptInfo. */ } JoinPath; @@ -303,7 +315,7 @@ typedef JoinPath NestPath; * A mergejoin path has these fields. * * path_mergeclauses lists the clauses (in the form of RestrictInfos) - * that will be used in the merge. (Before 7.0, this was a list of + * that will be used in the merge. (Before 7.0, this was a list of * bare clause expressions, but we can save on list memory by leaving * it in the form of a RestrictInfo list.) * @@ -321,7 +333,8 @@ typedef JoinPath NestPath; typedef struct MergePath { JoinPath jpath; - List *path_mergeclauses; /* join clauses to be used for merge */ + List *path_mergeclauses; /* join clauses to be used for + * merge */ List *outersortkeys; /* keys for explicit sort, if any */ List *innersortkeys; /* keys for explicit sort, if any */ } MergePath; @@ -340,14 +353,14 @@ typedef struct MergePath typedef struct HashPath { JoinPath jpath; - List *path_hashclauses; /* join clauses used for hashing */ + List *path_hashclauses; /* join clauses used for hashing */ } HashPath; /* * Restriction clause info. * * We create one of these for each AND sub-clause of a restriction condition - * (WHERE clause). Since the restriction clauses are logically ANDed, we + * (WHERE clause). Since the restriction clauses are logically ANDed, we * can use any one of them or any subset of them to filter out tuples, * without having to evaluate the rest. The RestrictInfo node itself stores * data used by the optimizer while choosing the best query plan. @@ -376,7 +389,7 @@ typedef struct HashPath * sequence we use. So, these clauses cannot be associated directly with * the join RelOptInfo, but must be kept track of on a per-join-path basis. * - * In general, the referenced clause might be arbitrarily complex. The + * In general, the referenced clause might be arbitrarily complex. The * kinds of clauses we can handle as indexscan quals, mergejoin clauses, * or hashjoin clauses are fairly limited --- the code for each kind of * path is responsible for identifying the restrict clauses it can use @@ -395,16 +408,16 @@ typedef struct RestrictInfo Expr *clause; /* the represented clause of WHERE cond */ /* only used if clause is an OR clause: */ - List *subclauseindices; /* indexes matching subclauses */ + List *subclauseindices; /* indexes matching subclauses */ /* subclauseindices is a List of Lists of IndexOptInfos */ /* valid if clause is mergejoinable, else InvalidOid: */ - Oid mergejoinoperator; /* copy of clause operator */ + Oid mergejoinoperator; /* copy of clause operator */ Oid left_sortop; /* leftside sortop needed for mergejoin */ Oid right_sortop; /* rightside sortop needed for mergejoin */ /* valid if clause is hashjoinable, else InvalidOid: */ - Oid hashjoinoperator; /* copy of clause operator */ + Oid hashjoinoperator; /* copy of clause operator */ } RestrictInfo; /* @@ -424,8 +437,8 @@ typedef struct RestrictInfo typedef struct JoinInfo { NodeTag type; - Relids unjoined_relids; /* some rels not yet part of my RelOptInfo */ - List *jinfo_restrictinfo; /* relevant RestrictInfos */ + Relids unjoined_relids;/* some rels not yet part of my RelOptInfo */ + List *jinfo_restrictinfo; /* relevant RestrictInfos */ } JoinInfo; /* @@ -463,7 +476,7 @@ typedef struct Stream StreamPtr downstream; bool groupup; Cost groupcost; - Selectivity groupsel; + Selectivity groupsel; } Stream; #endif /* RELATION_H */ |