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Reset API of clause_selectivity()

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Discussion: https://postgr.es/m/CAKJS1f9yurJQW9pdnzL+rmOtsp2vOytkpXKGnMFJEO-qz5O5eA@mail.gmail.com
This commit is contained in:
Simon Riggs
2017-04-06 19:10:51 -04:00
parent 255efa241f
commit ac2b095088
8 changed files with 74 additions and 60 deletions
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69
src/backend/optimizer/path/clausesel.c
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@@ -41,7 +41,8 @@ typedef struct RangeQueryClause
static void addRangeClause(RangeQueryClause **rqlist, Node *clause,
bool varonleft, bool isLTsel, Selectivity s2);
static RelOptInfo *find_relation_from_clauses(PlannerInfo *root,
List *clauses);
/****************************************************************************
* ROUTINES TO COMPUTE SELECTIVITIES
@@ -101,14 +102,14 @@ clauselist_selectivity(PlannerInfo *root,
List *clauses,
int varRelid,
JoinType jointype,
SpecialJoinInfo *sjinfo,
RelOptInfo *rel)
SpecialJoinInfo *sjinfo)
{
Selectivity s1 = 1.0;
RangeQueryClause *rqlist = NULL;
ListCell *l;
Bitmapset *estimatedclauses = NULL;
int listidx;
RelOptInfo *rel;
/*
* If there's exactly one clause, then extended statistics is futile at
@@ -117,7 +118,14 @@ clauselist_selectivity(PlannerInfo *root,
*/
if (list_length(clauses) == 1)
return clause_selectivity(root, (Node *) linitial(clauses),
varRelid, jointype, sjinfo, rel);
varRelid, jointype, sjinfo);
/*
* Determine if these clauses reference a single relation. If so we might
* like to try applying any extended statistics which exist on it.
* Called many time during joins, so must return NULL quickly if not.
*/
rel = find_relation_from_clauses(root, clauses);
/*
* When a relation of RTE_RELATION is given as 'rel', we'll try to
@@ -164,7 +172,7 @@ clauselist_selectivity(PlannerInfo *root,
continue;
/* Always compute the selectivity using clause_selectivity */
s2 = clause_selectivity(root, clause, varRelid, jointype, sjinfo, rel);
s2 = clause_selectivity(root, clause, varRelid, jointype, sjinfo);
/*
* Check for being passed a RestrictInfo.
@@ -417,6 +425,39 @@ addRangeClause(RangeQueryClause **rqlist, Node *clause,
*rqlist = rqelem;
}
/*
* find_relation_from_clauses
* Process each clause in 'clauses' and determine if all clauses
* reference only a single relation. If so return that relation,
* otherwise return NULL.
*/
static RelOptInfo *
find_relation_from_clauses(PlannerInfo *root, List *clauses)
{
ListCell *l;
int relid;
int lastrelid = 0;
foreach(l, clauses)
{
RestrictInfo *rinfo = (RestrictInfo *) lfirst(l);
if (bms_get_singleton_member(rinfo->clause_relids, &relid))
{
if (lastrelid != 0 && relid != lastrelid)
return NULL; /* relation not the same as last one */
lastrelid = relid;
}
else
return NULL; /* multiple relations in clause */
}
if (lastrelid != 0)
return find_base_rel(root, lastrelid);
return NULL; /* no clauses */
}
/*
* bms_is_subset_singleton
*
@@ -529,8 +570,7 @@ clause_selectivity(PlannerInfo *root,
Node *clause,
int varRelid,
JoinType jointype,
SpecialJoinInfo *sjinfo,
RelOptInfo *rel)
SpecialJoinInfo *sjinfo)
{
Selectivity s1 = 0.5; /* default for any unhandled clause type */
RestrictInfo *rinfo = NULL;
@@ -650,8 +690,7 @@ clause_selectivity(PlannerInfo *root,
(Node *) get_notclausearg((Expr *) clause),
varRelid,
jointype,
sjinfo,
rel);
sjinfo);
}
else if (and_clause(clause))
{
@@ -660,8 +699,7 @@ clause_selectivity(PlannerInfo *root,
((BoolExpr *) clause)->args,
varRelid,
jointype,
sjinfo,
rel);
sjinfo);
}
else if (or_clause(clause))
{
@@ -680,8 +718,7 @@ clause_selectivity(PlannerInfo *root,
(Node *) lfirst(arg),
varRelid,
jointype,
sjinfo,
rel);
sjinfo);
s1 = s1 + s2 - s1 * s2;
}
@@ -774,8 +811,7 @@ clause_selectivity(PlannerInfo *root,
(Node *) ((RelabelType *) clause)->arg,
varRelid,
jointype,
sjinfo,
rel);
sjinfo);
}
else if (IsA(clause, CoerceToDomain))
{
@@ -784,8 +820,7 @@ clause_selectivity(PlannerInfo *root,
(Node *) ((CoerceToDomain *) clause)->arg,
varRelid,
jointype,
sjinfo,
rel);
sjinfo);
}
else
{