diff options
Diffstat (limited to 'src/include/nodes/relation.h')
| -rw-r--r-- | src/include/nodes/relation.h | 57 |
1 files changed, 20 insertions, 37 deletions
diff --git a/src/include/nodes/relation.h b/src/include/nodes/relation.h index 7c702f7105a..ec839d7d3f6 100644 --- a/src/include/nodes/relation.h +++ b/src/include/nodes/relation.h @@ -7,7 +7,7 @@ * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/include/nodes/relation.h,v 1.112 2005/06/08 23:02:05 tgl Exp $ + * $PostgreSQL: pgsql/src/include/nodes/relation.h,v 1.113 2005/06/09 04:19:00 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -181,7 +181,7 @@ typedef struct PlannerInfo * and joins that the relation participates in: * * baserestrictinfo - List of RestrictInfo nodes, containing info about - * each qualification clause in which this relation + * each non-join qualification clause in which this relation * participates (only used for base rels) * baserestrictcost - Estimated cost of evaluating the baserestrictinfo * clauses at a single tuple (only used for base rels) @@ -189,8 +189,8 @@ typedef struct PlannerInfo * side of an outer join, the set of all relids * participating in the highest such outer join; else NULL. * Otherwise, unused. - * joininfo - List of JoinInfo nodes, containing info about each join - * clause in which this relation participates + * joininfo - List of RestrictInfo nodes, containing info about each + * join clause in which this relation participates * index_outer_relids - only used for base rels; set of outer relids * that participate in indexable joinclauses for this rel * index_inner_paths - only used for base rels; list of InnerIndexscanInfo @@ -206,7 +206,7 @@ typedef struct PlannerInfo * 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 + * the RelOptInfo to store the joininfo list, because that is the same * for a given rel no matter how we form it. * * We store baserestrictcost in the RelOptInfo (for base relations) because @@ -262,7 +262,8 @@ typedef struct RelOptInfo * base rel) */ QualCost baserestrictcost; /* cost of evaluating the above */ Relids outerjoinset; /* set of base relids */ - List *joininfo; /* JoinInfo structures */ + List *joininfo; /* RestrictInfo structures for join clauses + * involving this rel */ /* cached info about inner indexscan paths for relation: */ Relids index_outer_relids; /* other relids in indexable join @@ -645,8 +646,8 @@ typedef struct HashPath * in the baserestrictinfo list of the RelOptInfo for that base rel. * * If a restriction clause references more than one base rel, it will - * appear in the JoinInfo lists of every RelOptInfo that describes a strict - * subset of the base rels mentioned in the clause. The JoinInfo lists are + * appear in the joininfo list of every RelOptInfo that describes a strict + * subset of the base rels mentioned in the clause. The joininfo lists are * used to drive join tree building by selecting plausible join candidates. * The clause cannot actually be applied until we have built a join rel * containing all the base rels it references, however. @@ -676,8 +677,8 @@ typedef struct HashPath * pushed down to a lower level than its original syntactic placement in the * join tree would suggest. If an outer join prevents us from pushing a qual * down to its "natural" semantic level (the level associated with just the - * base rels used in the qual) then the qual will appear in JoinInfo lists - * that reference more than just the base rels it actually uses. By + * base rels used in the qual) then we mark the qual with a "required_relids" + * value including more than just the base rels it actually uses. By * pretending that the qual references all the rels appearing in the outer * join, we prevent it from being evaluated below the outer join's joinrel. * When we do form the outer join's joinrel, we still need to distinguish @@ -685,11 +686,11 @@ typedef struct HashPath * that appeared higher in the tree and were pushed down to the join rel * because they used no other rels. That's what the is_pushed_down flag is * for; it tells us that a qual came from a point above the join of the - * specific set of base rels that it uses (or that the JoinInfo structures - * claim it uses). A clause that originally came from WHERE will *always* - * have its is_pushed_down flag set; a clause that came from an INNER JOIN - * condition, but doesn't use all the rels being joined, will also have - * is_pushed_down set because it will get attached to some lower joinrel. + * set of base rels listed in required_relids. A clause that originally came + * from WHERE will *always* have its is_pushed_down flag set; a clause that + * came from an INNER JOIN condition, but doesn't use all the rels being + * joined, will also have is_pushed_down set because it will get attached to + * some lower joinrel. * * We also store a valid_everywhere flag, which says that the clause is not * affected by any lower-level outer join, and therefore any conditions it @@ -732,9 +733,12 @@ typedef struct RestrictInfo */ bool can_join; - /* The set of relids (varnos) referenced in the clause: */ + /* The set of relids (varnos) actually referenced in the clause: */ Relids clause_relids; + /* The set of relids required to evaluate the clause: */ + Relids required_relids; + /* These fields are set for any binary opclause: */ Relids left_relids; /* relids in left side of clause */ Relids right_relids; /* relids in right side of clause */ @@ -768,27 +772,6 @@ typedef struct RestrictInfo } RestrictInfo; /* - * Join clause info. - * - * We make a list of these for each RelOptInfo, containing info about - * all the join clauses this RelOptInfo participates in. (For this - * purpose, a "join clause" is a WHERE clause that mentions both vars - * belonging to this relation and vars belonging to relations not yet - * joined to it.) We group these clauses according to the set of - * other base relations (unjoined relations) mentioned in them. - * There is one JoinInfo for each distinct set of unjoined_relids, - * and its jinfo_restrictinfo lists the clause(s) that use that set - * of other relations. - */ - -typedef struct JoinInfo -{ - NodeTag type; - Relids unjoined_relids; /* some rels not yet part of my RelOptInfo */ - List *jinfo_restrictinfo; /* relevant RestrictInfos */ -} JoinInfo; - -/* * Inner indexscan info. * * An inner indexscan is one that uses one or more joinclauses as index |