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Clean up messy clause-selectivity code in clausesel.c; repair bug

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identified by Hiroshi (incorrect cost attributed to OR clauses
after multiple passes through set_rest_selec()).  I think the code
was trying to allow selectivities of OR subclauses to be passed in
from outside, but noplace was actually passing any useful data, and
set_rest_selec() was passing wrong data.

Restructure representation of "indexqual" in IndexPath nodes so that
it is the same as for indxqual in completed IndexScan nodes: namely,
a toplevel list with an entry for each pass of the index scan, having
sublists that are implicitly-ANDed index qual conditions for that pass.
You don't want to know what the old representation was :-(

Improve documentation of OR-clause indexscan functions.

Remove useless 'notclause' field from RestrictInfo nodes.  (This might
force an initdb for anyone who has stored rules containing RestrictInfos,
but I do not think that RestrictInfo ever appears in completed plans.)
This commit is contained in:
Tom Lane 1999-07-24 23:21:14 +00:00
parent 348bdbce79
commit ac4913a0dd
17 changed files with 471 additions and 519 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
src/backend/nodes/copyfuncs.c
View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.86 1999/07/17 20:17:05 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.87 1999/07/24 23:21:06 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -1317,7 +1317,6 @@ _copyRestrictInfo(RestrictInfo *from)
Node_Copy(from, newnode, clause);
newnode->selectivity = from->selectivity;
newnode->notclause = from->notclause;
Node_Copy(from, newnode, indexids);
Node_Copy(from, newnode, mergejoinorder);

4
src/backend/nodes/equalfuncs.c
View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v 1.43 1999/07/17 20:17:05 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v 1.44 1999/07/24 23:21:06 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -305,8 +305,6 @@ _equalRestrictInfo(RestrictInfo *a, RestrictInfo *b)
return false;
if (a->selectivity != b->selectivity)
return false;
if (a->notclause != b->notclause)
return false;
#ifdef EqualMergeOrderExists
if (!EqualMergeOrder(a->mergejoinorder, b->mergejoinorder))
return false;

7
src/backend/nodes/outfuncs.c
View File

@ -5,7 +5,7 @@
*
* Copyright (c) 1994, Regents of the University of California
*
* $Id: outfuncs.c,v 1.90 1999/07/18 19:02:49 tgl Exp $
* $Id: outfuncs.c,v 1.91 1999/07/24 23:21:07 tgl Exp $
*
* NOTES
* Every (plan) node in POSTGRES has an associated "out" routine which
@ -1110,9 +1110,8 @@ _outRestrictInfo(StringInfo str, RestrictInfo *node)
_outNode(str, node->clause);
appendStringInfo(str,
" :selectivity %f :notclause %s :indexids ",
node->selectivity,
node->notclause ? "true" : "false");
" :selectivity %f :indexids ",
node->selectivity);
_outNode(str, node->indexids);
appendStringInfo(str, " :mergejoinorder ");

10
src/backend/nodes/readfuncs.c
View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/nodes/readfuncs.c,v 1.69 1999/07/17 20:17:08 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/nodes/readfuncs.c,v 1.70 1999/07/24 23:21:08 tgl Exp $
*
* NOTES
* Most of the read functions for plan nodes are tested. (In fact, they
@ -1856,14 +1856,6 @@ _readRestrictInfo()
local_node->selectivity = atof(token);
token = lsptok(NULL, &length); /* get :notclause */
token = lsptok(NULL, &length); /* now read it */
if (!strncmp(token, "true", 4))
local_node->notclause = true;
else
local_node->notclause = false;
token = lsptok(NULL, &length); /* get :indexids */
local_node->indexids = nodeRead(true); /* now read it */

24
src/backend/optimizer/path/allpaths.c
View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/path/allpaths.c,v 1.50 1999/07/17 20:17:11 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/path/allpaths.c,v 1.51 1999/07/24 23:21:08 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -86,8 +86,8 @@ make_one_rel(Query *root, List *rels)
* set_base_rel_pathlist
* Finds all paths available for scanning each relation entry in
* 'rels'. Sequential scan and any available indices are considered
* if possible(indices are not considered for lower nesting levels).
* All unique paths are attached to the relation's 'pathlist' field.
* if possible (indices are not considered for lower nesting levels).
* All useful paths are attached to the relation's 'pathlist' field.
*
* MODIFIES: rels
*/
@ -98,21 +98,32 @@ set_base_rel_pathlist(Query *root, List *rels)
foreach(temp, rels)
{
RelOptInfo *rel = (RelOptInfo *) lfirst(temp);
List *indices = find_relation_indices(root, rel);
List *sequential_scan_list;
List *rel_index_scan_list;
List *or_index_scan_list;
RelOptInfo *rel = (RelOptInfo *) lfirst(temp);
sequential_scan_list = lcons(create_seqscan_path(rel), NIL);
rel_index_scan_list = create_index_paths(root,
rel,
find_relation_indices(root, rel),
indices,
rel->restrictinfo,
rel->joininfo);
or_index_scan_list = create_or_index_paths(root, rel, rel->restrictinfo);
/* Note: create_or_index_paths depends on create_index_paths
* to have marked OR restriction clauses with relevant indices;
* this is why it doesn't need to be given the full list of indices.
*/
or_index_scan_list = create_or_index_paths(root, rel,
rel->restrictinfo);
/* add_pathlist will discard any paths that are dominated by
* another available path, keeping only those paths that are
* superior along at least one dimension of cost or sortedness.
*/
rel->pathlist = add_pathlist(rel,
sequential_scan_list,
nconc(rel_index_scan_list,
@ -128,7 +139,6 @@ set_base_rel_pathlist(Query *root, List *rels)
rel->size = compute_rel_size(rel);
rel->width = compute_rel_width(rel);
}
return;
}
/*

363
src/backend/optimizer/path/clausesel.c
View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/path/clausesel.c,v 1.23 1999/07/16 04:59:14 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/path/clausesel.c,v 1.24 1999/07/24 23:21:09 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -23,32 +23,26 @@
#include "utils/lsyscache.h"
static Cost compute_selec(Query *root, List *clauses, List *or_selectivities);
/****************************************************************************
* ROUTINES TO SET CLAUSE SELECTIVITIES
****************************************************************************/
/*
* set_clause_selectivities -
* Sets the selectivity field for each of clause in 'restrictinfo-list'
* to 'new-selectivity'. If the selectivity has already been set, reset
* it only if the new one is better.
*
* Returns nothing of interest.
*
* Sets the selectivity field for each clause in 'restrictinfo-list'
* to 'new-selectivity'. If the selectivity has already been set,
* change it only if the new one is better.
*/
void
set_clause_selectivities(List *restrictinfo_list, Cost new_selectivity)
{
List *temp;
RestrictInfo *clausenode;
Cost cost_clause;
List *rlist;
foreach(temp, restrictinfo_list)
foreach(rlist, restrictinfo_list)
{
clausenode = (RestrictInfo *) lfirst(temp);
cost_clause = clausenode->selectivity;
RestrictInfo *clausenode = (RestrictInfo *) lfirst(rlist);
Cost cost_clause = clausenode->selectivity;
if (cost_clause <= 0 || new_selectivity < cost_clause)
clausenode->selectivity = new_selectivity;
}
@ -63,18 +57,12 @@ set_clause_selectivities(List *restrictinfo_list, Cost new_selectivity)
Cost
product_selec(List *restrictinfo_list)
{
Cost result = 1.0;
Cost result = (Cost) 1.0;
List *rlist;
if (restrictinfo_list != NIL)
foreach(rlist, restrictinfo_list)
{
List *xclausenode = NIL;
Cost temp;
foreach(xclausenode, restrictinfo_list)
{
temp = ((RestrictInfo *) lfirst(xclausenode))->selectivity;
result = result * temp;
}
result *= ((RestrictInfo *) lfirst(rlist))->selectivity;
}
return result;
}
@ -84,19 +72,16 @@ product_selec(List *restrictinfo_list)
* Scans through clauses on each relation and assigns a selectivity to
* those clauses that haven't been assigned a selectivity by an index.
*
* Returns nothing of interest.
* MODIFIES: selectivities of the various rel's restrictinfo
* slots.
* MODIFIES: selectivities of the various rel's restrictinfo slots.
*/
void
set_rest_relselec(Query *root, List *rel_list)
{
RelOptInfo *rel;
List *x;
foreach(x, rel_list)
{
rel = (RelOptInfo *) lfirst(x);
RelOptInfo *rel = (RelOptInfo *) lfirst(x);
set_rest_selec(root, rel->restrictinfo);
}
}
@ -105,31 +90,20 @@ set_rest_relselec(Query *root, List *rel_list)
* set_rest_selec -
* Sets the selectivity fields for those clauses within a single
* relation's 'restrictinfo-list' that haven't already been set.
*
* Returns nothing of interest.
*
*/
void
set_rest_selec(Query *root, List *restrictinfo_list)
{
List *temp = NIL;
RestrictInfo *clausenode = (RestrictInfo *) NULL;
Cost cost_clause;
List *rlist;
foreach(temp, restrictinfo_list)
foreach(rlist, restrictinfo_list)
{
clausenode = (RestrictInfo *) lfirst(temp);
cost_clause = clausenode->selectivity;
RestrictInfo *clause = (RestrictInfo *) lfirst(rlist);
/*
* Check to see if the selectivity of this clause or any 'or'
* subclauses (if any) haven't been set yet.
*/
if (cost_clause <= 0 || valid_or_clause(clausenode))
if (clause->selectivity <= 0)
{
clausenode->selectivity = compute_clause_selec(root,
(Node *) clausenode->clause,
lcons(makeFloat(cost_clause), NIL));
clause->selectivity =
compute_clause_selec(root, (Node *) clause->clause);
}
}
}
@ -140,89 +114,29 @@ set_rest_selec(Query *root, List *restrictinfo_list)
/*
* compute_clause_selec -
* Given a clause, this routine will compute the selectivity of the
* clause by calling 'compute_selec' with the appropriate parameters
* and possibly use that return value to compute the real selectivity
* of a clause.
*
* 'or-selectivities' are selectivities that have already been assigned
* to subclauses of an 'or' clause.
*
* Returns a flonum corresponding to the clause selectivity.
*
* Computes the selectivity of a clause.
*/
Cost
compute_clause_selec(Query *root, Node *clause, List *or_selectivities)
compute_clause_selec(Query *root, Node *clause)
{
if (is_opclause(clause))
return compute_selec(root, lcons(clause, NIL), or_selectivities);
else if (not_clause(clause))
{
/*
* 'not' gets "1.0 - selectivity-of-inner-clause".
*/
return (1.000000 - compute_selec(root,
lcons(get_notclausearg((Expr *) clause),
NIL),
or_selectivities));
}
else if (or_clause(clause))
{
/*
* Both 'or' and 'and' clauses are evaluated as described in
* (compute_selec).
*/
return compute_selec(root, ((Expr *) clause)->args, or_selectivities);
}
else
return compute_selec(root, lcons(clause, NIL), or_selectivities);
}
/*
* compute_selec -
* Computes the selectivity of a clause.
*
* If there is more than one clause in the argument 'clauses', then the
* desired selectivity is that of an 'or' clause. Selectivities for an
* 'or' clause such as (OR a b) are computed by finding the selectivity
* of a (s1) and b (s2) and computing s1+s2 - s1*s2.
*
* In addition, if the clause is an 'or' clause, individual selectivities
* may have already been assigned by indices to subclauses. These values
* are contained in the list 'or-selectivities'.
*
* Returns the clause selectivity as a flonum.
*
*/
static Cost
compute_selec(Query *root, List *clauses, List *or_selectivities)
{
Cost s1 = 0;
List *clause = lfirst(clauses);
Cost s1 = 1.0; /* default for any unhandled clause type */
if (clause == NULL)
s1 = 1.0;
else if (IsA(clause, Param))
return s1;
if (IsA(clause, Var))
{
/* XXX How're we handling this before?? -ay */
s1 = 1.0;
}
else if (IsA(clause, Const))
s1 = ((bool) ((Const *) clause)->constvalue) ? 1.0 : 0.0;
else if (IsA(clause, Var))
{
Oid relid = getrelid(((Var *) clause)->varno,
root->rtable);
/*
* we have a bool Var. This is exactly equivalent to the clause:
* reln.attribute = 't' so we compute the selectivity as if that
* is what we have. The magic #define constants are a hack. I
* didn't want to have to do system cache look ups to find out all
* of that info.
*
* XXX why are we using varno and varoattno? Seems like it should
* be varno/varattno or varnoold/varoattno, not mix & match...
*/
Oid relid = getrelid(((Var *) clause)->varno,
root->rtable);
s1 = restriction_selectivity(F_EQSEL,
BooleanEqualOperator,
@ -231,134 +145,141 @@ compute_selec(Query *root, List *clauses, List *or_selectivities)
"t",
_SELEC_CONSTANT_RIGHT_);
}
else if (or_selectivities)
else if (IsA(clause, Param))
{
/* If s1 has already been assigned by an index, use that value. */
List *this_sel = lfirst(or_selectivities);
s1 = floatVal(this_sel);
/* XXX any way to do better? */
s1 = 1.0;
}
else if (is_funcclause((Node *) clause))
else if (IsA(clause, Const))
{
/* bool constant is pretty easy... */
s1 = ((bool) ((Const *) clause)->constvalue) ? 1.0 : 0.0;
}
else if (not_clause(clause))
{
/* inverse of the selectivity of the underlying clause */
s1 = 1.0 - compute_clause_selec(root,
(Node *) get_notclausearg((Expr *) clause));
}
else if (and_clause(clause))
{
/* Use the product of the selectivities of the subclauses.
* XXX this is probably too optimistic, since the subclauses
* are very likely not independent...
*/
List *arg;
s1 = 1.0;
foreach(arg, ((Expr *) clause)->args)
{
Cost s2 = compute_clause_selec(root, (Node *) lfirst(arg));
s1 = s1 * s2;
}
}
else if (or_clause(clause))
{
/* Selectivities for an 'or' clause are computed as s1+s2 - s1*s2
* to account for the probable overlap of selected tuple sets.
* XXX is this too conservative?
*/
List *arg;
s1 = 0.0;
foreach(arg, ((Expr *) clause)->args)
{
Cost s2 = compute_clause_selec(root, (Node *) lfirst(arg));
s1 = s1 + s2 - s1 * s2;
}
}
else if (is_funcclause(clause))
{
/* this isn't an Oper, it's a Func!! */
/*
* This is not an operator, so we guess at the selectivity. THIS
* IS A HACK TO GET V4 OUT THE DOOR. FUNCS SHOULD BE ABLE TO HAVE
* SELECTIVITIES THEMSELVES. -- JMH 7/9/92
*/
s1 = 0.1;
s1 = (Cost) 0.3333333;
}
else if (not_clause((Node *) clause))
else if (is_subplan(clause))
{
/* negate this baby */
return 1 - compute_selec(root, ((Expr *) clause)->args, or_selectivities);
}
else if (is_subplan((Node *) clause))
{
/*
* Just for the moment! FIX ME! - vadim 02/04/98
*/
s1 = 1.0;
}
else if (NumRelids((Node *) clause) == 1)
else if (is_opclause(clause))
{
/*
* ...otherwise, calculate s1 from 'clauses'. The clause is not a
* join clause, since there is only one relid in the clause. The
* clause selectivity will be based on the operator selectivity
* and operand values.
*/
Oid opno = ((Oper *) ((Expr *) clause)->oper)->opno;
RegProcedure oprrest = get_oprrest(opno);
Oid relid;
int relidx;
AttrNumber attno;
Datum constval;
int flag;
get_relattval((Node *) clause, &relidx, &attno, &constval, &flag);
relid = getrelid(relidx, root->rtable);
/*
* if the oprrest procedure is missing for whatever reason, use a
* selectivity of 0.5
*/
if (!oprrest)
s1 = (Cost) (0.5);
else if (attno == InvalidAttrNumber)
if (NumRelids(clause) == 1)
{
/* The clause is not a join clause, since there is only one
* relid in the clause. The clause selectivity will be based on
* the operator selectivity and operand values.
*/
Oid opno = ((Oper *) ((Expr *) clause)->oper)->opno;
RegProcedure oprrest = get_oprrest(opno);
Oid relid;
int relidx;
AttrNumber attno;
Datum constval;
int flag;
get_relattval(clause, &relidx, &attno, &constval, &flag);
relid = getrelid(relidx, root->rtable);
/*
* attno can be Invalid if the clause had a function in it,
* i.e. WHERE myFunc(f) = 10
* if the oprrest procedure is missing for whatever reason, use a
* selectivity of 0.5
*/
/* this should be FIXED somehow to use function selectivity */
s1 = (Cost) (0.5);
if (!oprrest)
s1 = (Cost) 0.5;
else if (attno == InvalidAttrNumber)
{
/*
* attno can be Invalid if the clause had a function in it,
* i.e. WHERE myFunc(f) = 10
*/
/* this should be FIXED somehow to use function selectivity */
s1 = (Cost) (0.5);
}
else
s1 = (Cost) restriction_selectivity(oprrest,
opno,
relid,
attno,
(char *) constval,
flag);
}
else
s1 = (Cost) restriction_selectivity(oprrest,
opno,
relid,
attno,
(char *) constval,
flag);
{
/*
* The clause must be a join clause. The clause selectivity will
* be based on the relations to be scanned and the attributes they
* are to be joined on.
*/
Oid opno = ((Oper *) ((Expr *) clause)->oper)->opno;
RegProcedure oprjoin = get_oprjoin(opno);
int relid1,
relid2;
AttrNumber attno1,
attno2;
}
else
{
get_rels_atts(clause, &relid1, &attno1, &relid2, &attno2);
relid1 = getrelid(relid1, root->rtable);
relid2 = getrelid(relid2, root->rtable);
/*
* The clause must be a join clause. The clause selectivity will
* be based on the relations to be scanned and the attributes they
* are to be joined on.
*/
Oid opno = ((Oper *) ((Expr *) clause)->oper)->opno;
RegProcedure oprjoin = get_oprjoin(opno);
int relid1,
relid2;
AttrNumber attno1,
attno2;
get_rels_atts((Node *) clause, &relid1, &attno1, &relid2, &attno2);
relid1 = getrelid(relid1, root->rtable);
relid2 = getrelid(relid2, root->rtable);
/*
* if the oprjoin procedure is missing for whatever reason, use a
* selectivity of 0.5
*/
if (!oprjoin)
s1 = (Cost) (0.5);
else
s1 = (Cost) join_selectivity(oprjoin,
opno,
relid1,
attno1,
relid2,
attno2);
/*
* if the oprjoin procedure is missing for whatever reason, use a
* selectivity of 0.5
*/
if (!oprjoin)
s1 = (Cost) (0.5);
else
s1 = (Cost) join_selectivity(oprjoin,
opno,
relid1,
attno1,
relid2,
attno2);
}
}
/*
* A null clause list eliminates no tuples, so return a selectivity of
* 1.0. If there is only one clause, the selectivity is not that of
* an 'or' clause, but rather that of the single clause.
*/
if (lnext(clauses) == NIL)
return s1;
else
{
/* Compute selectivity of the 'or'ed subclauses. */
/* Added check for taking lnext(NIL). -- JMH 3/9/92 */
Cost s2;
if (or_selectivities != NIL)
s2 = compute_selec(root, lnext(clauses), lnext(or_selectivities));
else
s2 = compute_selec(root, lnext(clauses), NIL);
return s1 + s2 - s1 * s2;
}
return s1;
}

57
src/backend/optimizer/path/indxpath.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/path/indxpath.c,v 1.62 1999/07/23 03:34:49 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/path/indxpath.c,v 1.63 1999/07/24 23:21:09 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -109,12 +109,25 @@ create_index_paths(Query *root,
continue;
/*
* 1. Try matching the index against subclauses of an 'or' clause.
* The fields of the restrictinfo nodes are marked with lists of
* the matching indices. No paths are actually created. We
* currently only look to match the first key. We don't find
* multi-key index cases where an AND matches the first key, and
* the OR matches the second key.
* 1. Try matching the index against subclauses of restriction 'or'
* clauses (ie, 'or' clauses that reference only this relation).
* The restrictinfo nodes for the 'or' clauses are marked with lists
* of the matching indices. No paths are actually created now;
* that will be done in orindxpath.c after all indexes for the rel
* have been examined. (We need to do it that way because we can
* potentially use a different index for each subclause of an 'or',
* so we can't build a path for an 'or' clause until all indexes have
* been matched against it.)
*
* We currently only look to match the first key of each index against
* 'or' subclauses. There are cases where a later key of a multi-key
* index could be used (if other top-level clauses match earlier keys
* of the index), but our poor brains are hurting already...
*
* We don't even think about special handling of 'or' clauses that
* involve more than one relation, since they can't be processed by
* a single indexscan path anyway. Currently, cnfify() is certain
* to have restructured any such toplevel 'or' clauses anyway.
*/
match_index_orclauses(rel,
index,
@ -123,7 +136,7 @@ create_index_paths(Query *root,
restrictinfo_list);
/*
* 2. If the keys of this index match any of the available
* 2. If the keys of this index match any of the available non-'or'
* restriction clauses, then create a path using those clauses
* as indexquals.
*/
@ -179,11 +192,14 @@ create_index_paths(Query *root,
/*
* match_index_orclauses
* Attempt to match an index against subclauses within 'or' clauses.
* If the index does match, then the clause is marked with information
* about the index.
* Each subclause that does match is marked with the index's node.
*
* Essentially, this adds 'index' to the list of indices in the
* RestrictInfo field of each of the clauses which it matches.
* Essentially, this adds 'index' to the list of subclause indices in
* the RestrictInfo field of each of the 'or' clauses where it matches.
* NOTE: we can use storage in the RestrictInfo for this purpose because
* this processing is only done on single-relation restriction clauses.
* Therefore, we will never have indexes for more than one relation
* mentioned in the same RestrictInfo node's list.
*
* 'rel' is the node of the relation on which the index is defined.
* 'index' is the index node.
@ -204,12 +220,11 @@ match_index_orclauses(RelOptInfo *rel,
{
RestrictInfo *restrictinfo = (RestrictInfo *) lfirst(i);
if (valid_or_clause(restrictinfo))
if (restriction_is_or_clause(restrictinfo))
{
/*
* Mark the 'or' clause with a list of indices which match
* each of its subclauses. We add entries to the existing
* list, if any.
* Add this index to the subclause index list for each
* subclause that it matches.
*/
restrictinfo->indexids =
match_index_orclause(rel, index,
@ -253,7 +268,9 @@ match_index_orclause(RelOptInfo *rel,
List *index_list;
List *clist;
/* first time through, we create empty list of same length as OR clause */
/* first time through, we create list of same length as OR clause,
* containing an empty sublist for each subclause.
*/
if (!other_matching_indices)
{
matching_indices = NIL;
@ -1186,9 +1203,13 @@ index_innerjoin(Query *root, RelOptInfo *rel, List *clausegroup_list,
pathnode->path.pathorder->ord.sortop = index->ordering;
pathnode->path.pathkeys = NIL;
/* Note that we are making a pathnode for a single-scan indexscan;
* therefore, both indexid and indexqual should be single-element
* lists.
*/
pathnode->indexid = index->relids;
pathnode->indexkeys = index->indexkeys;
pathnode->indexqual = clausegroup;
pathnode->indexqual = lcons(get_actual_clauses(clausegroup), NIL);
pathnode->path.joinid = ((RestrictInfo *) lfirst(clausegroup))->restrictinfojoinid;

183
src/backend/optimizer/path/orindxpath.c
View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/path/orindxpath.c,v 1.28 1999/07/16 04:59:15 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/path/orindxpath.c,v 1.29 1999/07/24 23:21:10 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -26,61 +26,66 @@
#include "parser/parsetree.h"
static void best_or_subclause_indices(Query *root, RelOptInfo *rel, List *subclauses,
List *indices, List **indexids, Cost *cost, Cost *selec);
static void best_or_subclause_index(Query *root, RelOptInfo *rel, Expr *subclause,
List *indices, int *indexid, Cost *cost, Cost *selec);
static void best_or_subclause_indices(Query *root, RelOptInfo *rel,
List *subclauses, List *indices,
List **indexids,
Cost *cost, Cost *selec);
static void best_or_subclause_index(Query *root, RelOptInfo *rel,
Expr *subclause, List *indices,
int *indexid, Cost *cost, Cost *selec);
/*
* create_or_index_paths
* Creates index paths for indices that match 'or' clauses.
* create_index_paths() must already have been called.
*
* 'rel' is the relation entry for which the paths are to be defined on
* 'clauses' is the list of available restriction clause nodes
*
* Returns a list of these index path nodes.
* Returns a list of index path nodes.
*
*/
List *
create_or_index_paths(Query *root,
RelOptInfo *rel, List *clauses)
{
List *t_list = NIL;
List *path_list = NIL;
List *clist;
foreach(clist, clauses)
{
RestrictInfo *clausenode = (RestrictInfo *) (lfirst(clist));
RestrictInfo *clausenode = (RestrictInfo *) lfirst(clist);
/*
* Check to see if this clause is an 'or' clause, and, if so,
* whether or not each of the subclauses within the 'or' clause
* has been matched by an index (the 'Index field was set in
* (match_or) if no index matches a given subclause, one of the
* lists of index nodes returned by (get_index) will be 'nil').
* has been matched by an index. The information used was
* saved by create_index_paths().
*/
if (valid_or_clause(clausenode) &&
if (restriction_is_or_clause(clausenode) &&
clausenode->indexids)
{
List *temp = NIL;
List *index_list = NIL;
bool index_flag = true;
bool all_indexable = true;
List *temp;
index_list = clausenode->indexids;
foreach(temp, index_list)
foreach(temp, clausenode->indexids)
{
if (!lfirst(temp))
if (lfirst(temp) == NIL)
{
index_flag = false;
all_indexable = false;
break;
}
}
/* do they all have indexes? */
if (index_flag)
{ /* used to be a lisp every function */
if (all_indexable)
{
/*
* OK, build an IndexPath for this OR clause, using the
* best available index for each subclause.
*/
IndexPath *pathnode = makeNode(IndexPath);
List *indexids = NIL;
List *indexids;
List *orclause;
Cost cost;
Cost selec;
@ -98,16 +103,35 @@ create_or_index_paths(Query *root,
pathnode->path.pathorder->ordtype = SORTOP_ORDER;
/*
* This is an IndexScan, but it does index lookups based
* on the order of the fields specified in the WHERE
* clause, not in any order, so the sortop is NULL.
* This is an IndexScan, but the overall result will consist
* of tuples extracted in multiple passes (one for each
* subclause of the OR), so the result cannot be claimed
* to have any particular ordering.
*/
pathnode->path.pathorder->ord.sortop = NULL;
pathnode->path.pathkeys = NIL;
pathnode->indexqual = lcons(clausenode, NIL);
/*
* Generate an indexqual list from the OR clause's args.
* We want two levels of sublist: the first is implicit OR
* and the second is implicit AND. (Currently, we will never
* see a sub-AND-clause because of cnfify(), but someday maybe
* the code below will do something useful...)
*/
pathnode->indexqual = NIL;
foreach(orclause, clausenode->clause->args)
{
List *sublist;
if (and_clause(lfirst(orclause)))
sublist = ((Expr *) lfirst(orclause))->args;
else
sublist = lcons(lfirst(orclause), NIL);
pathnode->indexqual = lappend(pathnode->indexqual,
sublist);
}
pathnode->indexid = indexids;
pathnode->path.path_cost = cost;
clausenode->selectivity = (Cost) selec;
/*
* copy restrictinfo list into path for expensive function
@ -121,33 +145,28 @@ create_or_index_paths(Query *root,
if (XfuncMode != XFUNC_OFF)
((Path *) pathnode)->path_cost += xfunc_get_path_cost((Path) pathnode);
#endif
clausenode->selectivity = (Cost) selec;
t_list = lappend(t_list, pathnode);
path_list = lappend(path_list, pathnode);
}
}
}
return t_list;
return path_list;
}
/*
* best_or_subclause_indices
* Determines the best index to be used in conjunction with each subclause
* of an 'or' clause and the cost of scanning a relation using these
* indices. The cost is the sum of the individual index costs.
* indices. The cost is the sum of the individual index costs, since
* the executor will perform a scan for each subclause of the 'or'.
*
* 'rel' is the node of the relation on which the index is defined
* 'rel' is the node of the relation on which the indexes are defined
* 'subclauses' are the subclauses of the 'or' clause
* 'indices' are those index nodes that matched subclauses of the 'or'
* clause
* 'examined_indexids' is a list of those index ids to be used with
* subclauses that have already been examined
* 'subcost' is the cost of using the indices in 'examined_indexids'
* 'selec' is a list of all subclauses that have already been examined
*
* Returns a list of the indexids, cost, and selectivities of each
* subclause, e.g., ((i1 i2 i3) cost (s1 s2 s3)), where 'i' is an OID,
* 'cost' is a flonum, and 's' is a flonum.
* 'indices' is a list of sublists of the index nodes that matched each
* subclause of the 'or' clause
* '*indexids' gets a list of the best index ID to use for each subclause
* '*cost' gets the total cost of the path
* '*selec' gets the total selectivity of the path.
*/
static void
best_or_subclause_indices(Query *root,
@ -155,11 +174,12 @@ best_or_subclause_indices(Query *root,
List *subclauses,
List *indices,
List **indexids, /* return value */
Cost *cost, /* return value */
Cost *selec) /* return value */
Cost *cost, /* return value */
Cost *selec) /* return value */
{
List *slist;
*indexids = NIL;
*selec = (Cost) 0.0;
*cost = (Cost) 0.0;
@ -180,8 +200,6 @@ best_or_subclause_indices(Query *root,
indices = lnext(indices);
}
return;
}
/*
@ -193,10 +211,9 @@ best_or_subclause_indices(Query *root,
* 'rel' is the node of the relation on which the index is defined
* 'subclause' is the subclause
* 'indices' is a list of index nodes that match the subclause
*
* Returns a list (index_id index_subcost index_selectivity)
* (a fixnum, a fixnum, and a flonum respectively).
*
* '*retIndexid' gets the ID 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,
@ -207,49 +224,60 @@ best_or_subclause_index(Query *root,
Cost *retCost, /* return value */
Cost *retSelec) /* return value */
{
List *ilist;
Oid relid = getrelid(lfirsti(rel->relids),
root->rtable);
Oid opno = ((Oper *) subclause->oper)->opno;
AttrNumber attno = (get_leftop(subclause))->varattno;
bool constant_on_right = non_null((Expr *) get_rightop(subclause));
Datum value;
int flag;
List *opnos,
*attnos,
*values,
*flags;
bool first_run = true;
List *ilist;
/* if we don't match anything, return zeros */
*retIndexid = 0;
*retCost = 0.0;
*retSelec = 0.0;
*retCost = (Cost) 0.0;
*retSelec = (Cost) 0.0;
if (constant_on_right) /* XXX looks pretty bogus ... tgl */
value = ((Const *) get_rightop(subclause))->constvalue;
else
value = NameGetDatum("");
if (constant_on_right)
flag = (_SELEC_IS_CONSTANT_ || _SELEC_CONSTANT_RIGHT_);
else
flag = _SELEC_CONSTANT_RIGHT_;
/* prebuild lists since we will pass same list to each index */
opnos = lconsi(opno, NIL);
attnos = lconsi(attno, NIL);
values = lconsi(value, NIL);
flags = lconsi(flag, NIL);
foreach(ilist, indices)
{
RelOptInfo *index = (RelOptInfo *) lfirst(ilist);
Datum value;
int flag = 0;
Oid indexid = (Oid) lfirsti(index->relids);
Cost subcost;
AttrNumber attno = (get_leftop(subclause))->varattno;
Oid opno = ((Oper *) subclause->oper)->opno;
bool constant_on_right = non_null((Expr *) get_rightop(subclause));
float npages,
selec;
if (constant_on_right)
value = ((Const *) get_rightop(subclause))->constvalue;
else
value = NameGetDatum("");
if (constant_on_right)
flag = (_SELEC_IS_CONSTANT_ || _SELEC_CONSTANT_RIGHT_);
else
flag = _SELEC_CONSTANT_RIGHT_;
index_selectivity(lfirsti(index->relids),
index_selectivity(indexid,
index->classlist,
lconsi(opno, NIL),
getrelid(lfirsti(rel->relids),
root->rtable),
lconsi(attno, NIL),
lconsi(value, NIL),
lconsi(flag, NIL),
opnos,
relid,
attnos,
values,
flags,
1,
&npages,
&selec);
subcost = cost_index((Oid) lfirsti(index->relids),
subcost = cost_index(indexid,
(int) npages,
(Cost) selec,
rel->pages,
@ -260,12 +288,11 @@ best_or_subclause_index(Query *root,
if (first_run || subcost < *retCost)
{
*retIndexid = lfirsti(index->relids);
*retIndexid = indexid;
*retCost = subcost;
*retSelec = selec;
first_run = false;
}
}
return;
}

108
src/backend/optimizer/plan/createplan.c
View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/plan/createplan.c,v 1.62 1999/07/17 20:17:13 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/plan/createplan.c,v 1.63 1999/07/24 23:21:11 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -301,54 +301,30 @@ create_seqscan_node(Path *best_path, List *tlist, List *scan_clauses)
* create_indexscan_node
* Returns a indexscan node for the base relation scanned by 'best_path'
* with restriction clauses 'scan_clauses' and targetlist 'tlist'.
*
* If an 'or' clause is to be used with this index, the indxqual field
* will contain a list of the 'or' clause arguments, e.g., the
* clause(OR a b c) will generate: ((a) (b) (c)). Otherwise, the
* indxqual will simply contain one conjunctive qualification: ((a)).
*/
static IndexScan *
create_indexscan_node(IndexPath *best_path,
List *tlist,
List *scan_clauses)
{
/*
* Extract the(first if conjunct, only if disjunct) clause from the
* restrictinfo list.
*/
Expr *index_clause = (Expr *) NULL;
List *indxqual = NIL;
List *qpqual = NIL;
List *fixed_indxqual = NIL;
List *indxqual = best_path->indexqual;
List *qpqual;
List *fixed_indxqual;
List *ixid;
IndexScan *scan_node = (IndexScan *) NULL;
bool lossy = FALSE;
HeapTuple indexTuple;
Form_pg_index index;
/*
* If an 'or' clause is to be used with this index, the indxqual field
* will contain a list of the 'or' clause arguments, e.g., the
* clause(OR a b c) will generate: ((a) (b) (c)). Otherwise, the
* indxqual will simply contain one conjunctive qualification: ((a)).
*/
if (best_path->indexqual != NULL)
/* added call to fix_opids, JMH 6/23/92 */
index_clause = (Expr *)
lfirst(fix_opids(get_actual_clauses(best_path->indexqual)));
if (or_clause((Node *) index_clause))
{
List *temp = NIL;
foreach(temp, index_clause->args)
indxqual = lappend(indxqual, lcons(lfirst(temp), NIL));
}
else
{
indxqual = lcons(get_actual_clauses(best_path->indexqual),
NIL);
}
IndexScan *scan_node;
bool lossy = false;
/* check and see if any indices are lossy */
foreach(ixid, best_path->indexid)
{
HeapTuple indexTuple;
Form_pg_index index;
indexTuple = SearchSysCacheTuple(INDEXRELID,
ObjectIdGetDatum(lfirsti(ixid)),
0, 0, 0);
@ -356,34 +332,70 @@ create_indexscan_node(IndexPath *best_path,
elog(ERROR, "create_plan: index %u not found", lfirsti(ixid));
index = (Form_pg_index) GETSTRUCT(indexTuple);
if (index->indislossy)
lossy = TRUE;
{
lossy = true;
break;
}
}
/*
* The qpqual field contains all restrictions not automatically
* The qpqual list must contain all restrictions not automatically
* handled by the index. Note that for non-lossy indices, the
* predicates in the indxqual are handled by the index, while for
* lossy indices the indxqual predicates need to be double-checked
* after the index fetches the best-guess tuples.
*
* There should not be any clauses in scan_clauses that duplicate
* expressions checked by the index, but just in case, we will
* get rid of them via set_difference.
*/
if (or_clause((Node *) index_clause))
if (length(indxqual) > 1)
{
/*
* Build an expression representation of the indexqual, expanding
* the implicit OR and AND semantics of the first- and second-level
* lists. XXX Is it really necessary to do a deep copy here?
*/
List *orclauses = NIL;
List *orclause;
Expr *indxqual_expr;
foreach(orclause, indxqual)
{
orclauses = lappend(orclauses,
make_ands_explicit((List *) copyObject(lfirst(orclause))));
}
indxqual_expr = make_orclause(orclauses);
/* this set_difference is almost certainly a waste of time... */
qpqual = set_difference(scan_clauses,
lcons(index_clause, NIL));
lcons(indxqual_expr, NIL));
if (lossy)
qpqual = lappend(qpqual, (List *) copyObject(index_clause));
qpqual = lappend(qpqual, indxqual_expr);
}
else
else if (indxqual != NIL)
{
/* Here, we can simply treat the first sublist as an independent
* set of qual expressions, since there is no top-level OR behavior.
*/
qpqual = set_difference(scan_clauses, lfirst(indxqual));
if (lossy)
qpqual = nconc(qpqual,
(List *) copyObject(lfirst(indxqual)));
qpqual = nconc(qpqual, (List *) copyObject(lfirst(indxqual)));
}
else
qpqual = NIL;
fixed_indxqual = (List *) fix_indxqual_references((Node *) indxqual, (Path *) best_path);
/*
* Fix opids in the completed indxqual. We don't want to do this sooner
* since it would screw up the set_difference calcs above. Really,
* this ought to only happen at final exit from the planner...
*/
indxqual = fix_opids(indxqual);
/* The executor needs a copy with index attrs substituted for table ones */
fixed_indxqual = (List *) fix_indxqual_references((Node *) indxqual,
(Path *) best_path);
scan_node = make_indexscan(tlist,
qpqual,

121
src/backend/optimizer/plan/initsplan.c
View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/plan/initsplan.c,v 1.34 1999/07/16 04:59:19 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/plan/initsplan.c,v 1.35 1999/07/24 23:21:12 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -25,12 +25,11 @@
#include "optimizer/var.h"
#include "utils/lsyscache.h"
extern int Quiet;
static void add_restrict_and_join_to_rel(Query *root, List *clause);
static void add_restrict_and_join_to_rel(Query *root, Node *clause);
static void add_join_info_to_rels(Query *root, RestrictInfo *restrictinfo,
Relids join_relids);
static void add_vars_to_targetlist(Query *root, List *vars, Relids join_relids);
static void add_vars_to_targetlist(Query *root, List *vars);
static MergeOrder *mergejoinop(Expr *clause);
static Oid hashjoinop(Expr *clause);
@ -129,7 +128,7 @@ add_missing_vars_to_tlist(Query *root, List *tlist)
* relations appearing within clauses. Creates new relation entries if
* necessary, adding them to *query_relation_list*.
*
* Returns nothing of interest.
* 'clauses': the list of clauses in the cnfify'd query qualification.
*/
void
add_restrict_and_join_to_rels(Query *root, List *clauses)
@ -137,95 +136,71 @@ add_restrict_and_join_to_rels(Query *root, List *clauses)
List *clause;
foreach(clause, clauses)
add_restrict_and_join_to_rel(root, lfirst(clause));
return;
add_restrict_and_join_to_rel(root, (Node*) lfirst(clause));
}
/*
* add_restrict_and_join_to_rel-
* Add clause information to either the 'RestrictInfo' or 'JoinInfo' field
* of a relation entry(depending on whether or not the clause is a join)
* of a relation entry (depending on whether or not the clause is a join)
* by creating a new RestrictInfo node and setting appropriate fields
* within the nodes.
*
* Returns nothing of interest.
*/
static void
add_restrict_and_join_to_rel(Query *root, List *clause)
add_restrict_and_join_to_rel(Query *root, Node *clause)
{
RestrictInfo *restrictinfo = makeNode(RestrictInfo);
Relids relids;
List *vars;
RestrictInfo *restrictinfo = makeNode(RestrictInfo);
/*
* Retrieve all relids and vars contained within the clause.
*/
clause_get_relids_vars((Node *) clause, &relids, &vars);
restrictinfo->clause = (Expr *) clause;
restrictinfo->notclause = contains_not((Node *) clause);
restrictinfo->selectivity = 0;
restrictinfo->indexids = NIL;
restrictinfo->mergejoinorder = (MergeOrder *) NULL;
restrictinfo->hashjoinoperator = (Oid) 0;
/*
* The selectivity of the clause must be computed regardless of
* whether it's a restriction or a join clause
*/
restrictinfo->selectivity = compute_clause_selec(root, clause);
/*
* Retrieve all relids and vars contained within the clause.
*/
clause_get_relids_vars(clause, &relids, &vars);
if (length(relids) == 1)
{
/*
* There is only one relation participating in 'clause', so
* 'clause' must be a restriction clause.
* 'clause' must be a restriction clause for that relation.
*/
RelOptInfo *rel = get_base_rel(root, lfirsti(relids));
/*
* The selectivity of the clause must be computed regardless of
* whether it's a restriction or a join clause
*/
if (is_funcclause((Node *) clause))
/*
* XXX If we have a func clause set selectivity to 1/3, really
* need a true selectivity function.
*/
restrictinfo->selectivity = (Cost) 0.3333333;
else
restrictinfo->selectivity = compute_clause_selec(root, (Node *) clause, NIL);
rel->restrictinfo = lcons(restrictinfo, rel->restrictinfo);
}
else
{
/*
* 'clause' is a join clause, since there is more than one atom in
* the relid list.
* the relid list. Add it to the join lists of all the relevant
* relations. (If, perchance, 'clause' contains NO vars, then
* nothing will happen...)
*/
if (is_funcclause((Node *) clause))
/*
* XXX If we have a func clause set selectivity to 1/3, really
* need a true selectivity function.
*/
restrictinfo->selectivity = (Cost) 0.3333333;
else
restrictinfo->selectivity = compute_clause_selec(root, (Node *) clause, NIL);
add_join_info_to_rels(root, restrictinfo, relids);
/* we are going to be doing a join, so add var to targetlist */
add_vars_to_targetlist(root, vars, relids);
/* we are going to be doing a join, so add vars to targetlists */
add_vars_to_targetlist(root, vars);
}
}
/*
* add_join_info_to_rels
* For every relation participating in a join clause, add 'restrictinfo' to
* the appropriate joininfo node(creating a new one and adding it to the
* the appropriate joininfo node (creating a new one and adding it to the
* appropriate rel node if necessary).
*
* 'restrictinfo' describes the join clause
* 'join_relids' is the list of relations participating in the join clause
*
*/
static void
add_join_info_to_rels(Query *root, RestrictInfo *restrictinfo,
@ -233,7 +208,7 @@ add_join_info_to_rels(Query *root, RestrictInfo *restrictinfo,
{
List *join_relid;
/* For every relid, find the rel, and add the proper join entries */
/* For every relid, find the joininfo, and add the proper join entries */
foreach(join_relid, join_relids)
{
JoinInfo *joininfo;
@ -247,43 +222,39 @@ add_join_info_to_rels(Query *root, RestrictInfo *restrictinfo,
unjoined_relids = lappendi(unjoined_relids, lfirsti(rel));
}
/*
* Find or make the joininfo node for this combination of rels
*/
joininfo = find_joininfo_node(get_base_rel(root, lfirsti(join_relid)),
unjoined_relids);
/*
* And add the restrictinfo node to it. NOTE that each joininfo
* gets its own copy of the restrictinfo node! (Is this really
* necessary? Possibly ... later parts of the optimizer destructively
* modify restrict/join clauses...)
*/
joininfo->jinfo_restrictinfo = lcons(copyObject((void *) restrictinfo),
joininfo->jinfo_restrictinfo);
joininfo->jinfo_restrictinfo);
}
}
/*
* add_vars_to_targetlist
* For each variable appearing in a clause,
* (1) If a targetlist entry for the variable is not already present in
* the appropriate relation's target list, add one.
* (2) If a targetlist entry is already present, but the var is part of a
* join clause, add the relids of the join relations to the JoinList
* entry of the targetlist entry.
*
* 'vars' is the list of var nodes
* 'join_relids' is the list of relids appearing in the join clause
* (if this is a join clause)
*
* Returns nothing.
* For each variable appearing in a clause, add it to the relation's
* targetlist if not already present.
*/
static void
add_vars_to_targetlist(Query *root, List *vars, Relids join_relids)
add_vars_to_targetlist(Query *root, List *vars)
{
Var *var;
List *temp = NIL;
RelOptInfo *rel = (RelOptInfo *) NULL;
TargetEntry *tlistentry;
List *temp;
foreach(temp, vars)
{
var = (Var *) lfirst(temp);
rel = get_base_rel(root, var->varno);
tlistentry = tlistentry_member(var, rel->targetlist);
if (tlistentry == NULL)
/* add a new entry */
Var *var = (Var *) lfirst(temp);
RelOptInfo *rel = get_base_rel(root, var->varno);
if (tlistentry_member(var, rel->targetlist) == NULL)
add_var_to_tlist(rel, var);
}
}

49
src/backend/optimizer/util/clauses.c
View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/util/clauses.c,v 1.40 1999/07/16 04:59:23 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/util/clauses.c,v 1.41 1999/07/24 23:21:13 tgl Exp $
*
* HISTORY
* AUTHOR DATE MAJOR EVENT
@ -290,6 +290,21 @@ make_andclause(List *andclauses)
return expr;
}
/*
* Sometimes (such as in the result of cnfify), we use lists of expression
* nodes with implicit AND semantics. This function converts back to an
* explicit-AND representation.
*/
Expr *
make_ands_explicit(List *andclauses)
{
if (andclauses == NIL)
return NULL;
else if (length(andclauses) == 1)
return (Expr *) lfirst(andclauses);
else
return make_andclause(andclauses);
}
/*****************************************************************************
* CASE clause functions
@ -410,38 +425,6 @@ NumRelids(Node *clause)
return length(var_list);
}
/*
* contains_not
*
* Returns t iff the clause is a 'not' clause or if any of the
* subclauses within an 'or' clause contain 'not's.
*
* NOTE that only the top-level AND/OR structure is searched for NOTs;
* we are not interested in buried substructure.
*/
bool
contains_not(Node *clause)
{
if (single_node(clause))
return false;
if (not_clause(clause))
return true;
if (or_clause(clause) || and_clause(clause))
{
List *a;
foreach(a, ((Expr *) clause)->args)
{
if (contains_not(lfirst(a)))
return true;
}
}
return false;
}
/*
* is_joinable
*

5
src/backend/optimizer/util/pathnode.c
View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/util/pathnode.c,v 1.46 1999/07/16 04:59:25 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/util/pathnode.c,v 1.47 1999/07/24 23:21:14 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -426,7 +426,8 @@ create_index_path(Query *root,
/* each clause gets an equal selectivity */
clausesel = pow(selec, 1.0 / (double) length(restriction_clauses));
pathnode->indexqual = restriction_clauses;
pathnode->indexqual = lcons(get_actual_clauses(restriction_clauses),
NIL);
pathnode->path.path_cost = cost_index(lfirsti(index->relids),
(int) npages,
selec,

10
src/backend/optimizer/util/restrictinfo.c
View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/util/restrictinfo.c,v 1.6 1999/07/16 04:59:27 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/util/restrictinfo.c,v 1.7 1999/07/24 23:21:14 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -20,17 +20,15 @@
#include "optimizer/restrictinfo.h"
/*
* valid_or_clause
* restriction_is_or_clause
*
* Returns t iff the restrictinfo node contains a 'normal' 'or' clause.
* Returns t iff the restrictinfo node contains an 'or' clause.
*
*/
bool
valid_or_clause(RestrictInfo *restrictinfo)
restriction_is_or_clause(RestrictInfo *restrictinfo)
{
if (restrictinfo != NULL &&
!single_node((Node *) restrictinfo->clause) &&
!restrictinfo->notclause &&
or_clause((Node *) restrictinfo->clause))
return true;
else

33
src/include/nodes/relation.h
View File

@ -6,7 +6,7 @@
*
* Copyright (c) 1994, Regents of the University of California
*
* $Id: relation.h,v 1.34 1999/07/15 23:03:56 momjian Exp $
* $Id: relation.h,v 1.35 1999/07/24 23:21:04 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -151,6 +151,23 @@ typedef struct Path
List *loc_restrictinfo;
} Path;
/*----------
* 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
* 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.
* 'indexqual' is a list of index qualifications, also one per scan.
* Each entry in 'indexqual' is a sublist of qualification expressions with
* implicit AND semantics across the sublist items. Each one of the sublist
* items must be an operator expression of the form (var op something) or
* (something op var), where the var is a field the associated index keys on
* and the op is a member of the operator class of the index.
* NOTE that the semantics of the top-level list in 'indexqual' is OR
* combination, while the sublists are implicitly AND combinations!
*----------
*/
typedef struct IndexPath
{
Path path;
@ -205,16 +222,20 @@ typedef struct JoinKey
} JoinKey;
/*
* clause info
* 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
* 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.
*/
typedef struct RestrictInfo
{
NodeTag type;
Expr *clause; /* should be an OP clause */
Cost selectivity;
bool notclause;
List *indexids;
Expr *clause; /* the represented subclause of WHERE cond */
Cost selectivity; /* estimated selectivity */
List *indexids; /* subclause index IDs if clause is an OR */
/* mergejoin only */
MergeOrder *mergejoinorder;

4
src/include/optimizer/clauses.h
View File

@ -6,7 +6,7 @@
*
* Copyright (c) 1994, Regents of the University of California
*
* $Id: clauses.h,v 1.21 1999/07/15 23:03:57 momjian Exp $
* $Id: clauses.h,v 1.22 1999/07/24 23:21:05 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -34,13 +34,13 @@ extern Expr *get_notclausearg(Expr *notclause);
extern bool and_clause(Node *clause);
extern Expr *make_andclause(List *andclauses);
extern Expr *make_ands_explicit(List *andclauses);
extern bool case_clause(Node *clause);
extern List *pull_constant_clauses(List *quals, List **constantQual);
extern void clause_get_relids_vars(Node *clause, Relids *relids, List **vars);
extern int NumRelids(Node *clause);
extern bool contains_not(Node *clause);
extern bool is_joinable(Node *clause);
extern bool qual_clause_p(Node *clause);
extern void fix_opid(Node *clause);

5
src/include/optimizer/cost.h
View File

@ -6,7 +6,7 @@
*
* Copyright (c) 1994, Regents of the University of California
*
* $Id: cost.h,v 1.21 1999/07/15 15:21:20 momjian Exp $
* $Id: cost.h,v 1.22 1999/07/24 23:21:05 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -59,7 +59,6 @@ extern void set_clause_selectivities(List *restrictinfo_list, Cost new_selectivi
extern Cost product_selec(List *restrictinfo_list);
extern void set_rest_relselec(Query *root, List *rel_list);
extern void set_rest_selec(Query *root, List *restrictinfo_list);
extern Cost compute_clause_selec(Query *root,
Node *clause, List *or_selectivities);
extern Cost compute_clause_selec(Query *root, Node *clause);
#endif /* COST_H */

4
src/include/optimizer/restrictinfo.h
View File

@ -6,7 +6,7 @@
*
* Copyright (c) 1994, Regents of the University of California
*
* $Id: restrictinfo.h,v 1.5 1999/07/15 15:21:23 momjian Exp $
* $Id: restrictinfo.h,v 1.6 1999/07/24 23:21:05 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -15,7 +15,7 @@
#include "nodes/relation.h"
extern bool valid_or_clause(RestrictInfo *restrictinfo);
extern bool restriction_is_or_clause(RestrictInfo *restrictinfo);
extern List *get_actual_clauses(List *restrictinfo_list);
extern void get_relattvals(List *restrictinfo_list, List **attnos,
List **values, List **flags);