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Another round of planner/optimizer work. This is just restructuring and

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code cleanup; no major improvements yet.  However, EXPLAIN does produce
more intuitive outputs for nested loops with indexscans now...
This commit is contained in:
Tom Lane
2000-01-09 00:26:47 +00:00
parent 69d4299e3e
commit 166b5c1def
35 changed files with 1239 additions and 1448 deletions
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79
src/backend/optimizer/path/orindxpath.c
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@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/path/orindxpath.c,v 1.32 1999/08/16 02:17:52 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/path/orindxpath.c,v 1.33 2000/01/09 00:26:33 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -30,11 +30,11 @@ static void best_or_subclause_indices(Query *root, RelOptInfo *rel,
List *subclauses, List *indices,
List **indexquals,
List **indexids,
Cost *cost, Cost *selec);
Cost *cost);
static void best_or_subclause_index(Query *root, RelOptInfo *rel,
List *indexqual, List *indices,
int *retIndexid,
Cost *retCost, Cost *retSelec);
Oid *retIndexid,
Cost *retCost);
/*
@ -89,7 +89,6 @@ create_or_index_paths(Query *root,
List *indexquals;
List *indexids;
Cost cost;
Cost selec;
best_or_subclause_indices(root,
rel,
@ -97,8 +96,7 @@ create_or_index_paths(Query *root,
clausenode->subclauseindices,
&indexquals,
&indexids,
&cost,
&selec);
&cost);
pathnode->path.pathtype = T_IndexScan;
pathnode->path.parent = rel;
@ -114,7 +112,6 @@ create_or_index_paths(Query *root,
pathnode->indexqual = indexquals;
pathnode->joinrelids = NIL; /* no join clauses here */
pathnode->path.path_cost = cost;
clausenode->selectivity = (Cost) selec;
path_list = lappend(path_list, pathnode);
}
@ -141,13 +138,12 @@ create_or_index_paths(Query *root,
*
* 'rel' is the node of the relation on which the indexes are defined
* 'subclauses' are the subclauses of the 'or' clause
* 'indices' is a list of sublists of the index nodes that matched each
* subclause of the 'or' clause
* 'indices' is a list of sublists of the IndexOptInfo nodes that matched
* each subclause of the 'or' clause
* '*indexquals' gets the constructed indexquals for the path (a list
* of sublists of clauses, one sublist per scan of the base rel)
* '*indexids' gets a list of the index IDs for each scan of the rel
* '*indexids' gets a list of the index OIDs for each scan of the rel
* '*cost' gets the total cost of the path
* '*selec' gets the total selectivity of the path.
*/
static void
best_or_subclause_indices(Query *root,
@ -156,23 +152,20 @@ best_or_subclause_indices(Query *root,
List *indices,
List **indexquals, /* return value */
List **indexids, /* return value */
Cost *cost, /* return value */
Cost *selec) /* return value */
Cost *cost) /* return value */
{
List *slist;
*indexquals = NIL;
*indexids = NIL;
*cost = (Cost) 0.0;
*selec = (Cost) 0.0;
foreach(slist, subclauses)
{
Expr *subclause = lfirst(slist);
List *indexqual;
int best_indexid;
Oid best_indexid;
Cost best_cost;
Cost best_selec;
/* Convert this 'or' subclause to an indexqual list */
indexqual = make_ands_implicit(subclause);
@ -180,18 +173,13 @@ best_or_subclause_indices(Query *root,
indexqual = expand_indexqual_conditions(indexqual);
best_or_subclause_index(root, rel, indexqual, lfirst(indices),
&best_indexid, &best_cost, &best_selec);
&best_indexid, &best_cost);
Assert(best_indexid != InvalidOid);
*indexquals = lappend(*indexquals, indexqual);
*indexids = lappendi(*indexids, best_indexid);
*cost += best_cost;
/* We approximate the selectivity as the sum of the clause
* selectivities (but not more than 1).
* XXX This is too pessimistic, isn't it?
*/
*selec += best_selec;
if (*selec > (Cost) 1.0)
*selec = (Cost) 1.0;
indices = lnext(indices);
}
@ -205,59 +193,50 @@ best_or_subclause_indices(Query *root,
*
* 'rel' is the node of the relation on which the index is defined
* 'indexqual' is the indexqual list derived from the subclause
* 'indices' is a list of index nodes that match the subclause
* '*retIndexid' gets the ID of the best index
* 'indices' is a list of IndexOptInfo nodes that match the subclause
* '*retIndexid' gets the OID of the best index
* '*retCost' gets the cost of a scan with that index
* '*retSelec' gets the selectivity of that scan
*/
static void
best_or_subclause_index(Query *root,
RelOptInfo *rel,
List *indexqual,
List *indices,
int *retIndexid, /* return value */
Cost *retCost, /* return value */
Cost *retSelec) /* return value */
Oid *retIndexid, /* return value */
Cost *retCost) /* return value */
{
bool first_run = true;
List *ilist;
/* if we don't match anything, return zeros */
*retIndexid = 0;
*retCost = (Cost) 0.0;
*retSelec = (Cost) 0.0;
*retIndexid = InvalidOid;
*retCost = 0.0;
foreach(ilist, indices)
{
RelOptInfo *index = (RelOptInfo *) lfirst(ilist);
Oid indexid = (Oid) lfirsti(index->relids);
IndexOptInfo *index = (IndexOptInfo *) lfirst(ilist);
long npages;
Selectivity selec;
Cost subcost;
float npages;
float selec;
Assert(IsA(index, IndexOptInfo));
index_selectivity(root,
lfirsti(rel->relids),
indexid,
rel,
index,
indexqual,
&npages,
&selec);
subcost = cost_index(indexid,
(int) npages,
(Cost) selec,
rel->pages,
rel->tuples,
index->pages,
index->tuples,
subcost = cost_index(rel, index,
npages, selec,
false);
if (first_run || subcost < *retCost)
{
*retIndexid = indexid;
*retIndexid = index->indexoid;
*retCost = subcost;
*retSelec = selec;
first_run = false;
}
}
}