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Commit9a586fe

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Nab some low-hanging fruit: replace the planner's base_rel_list and
other_rel_list with a single array indexed by rangetable index.This reduces find_base_rel from O(N) to O(1) without any real penalty.While find_base_rel isn't one of the major bottlenecks in any profileI've seen so far, it was starting to creep up on the radar screenfor complex queries --- so might as well fix it.
1 parent9ab4d98 commit9a586fe

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5 files changed

+142
-109
lines changed

5 files changed

+142
-109
lines changed

‎src/backend/nodes/outfuncs.c‎

Lines changed: 2 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $PostgreSQL: pgsql/src/backend/nodes/outfuncs.c,v 1.253 2005/06/05 22:32:54 tgl Exp $
11+
* $PostgreSQL: pgsql/src/backend/nodes/outfuncs.c,v 1.254 2005/06/06 04:13:35 tgl Exp $
1212
*
1313
* NOTES
1414
* Every node type that can appear in stored rules' parsetrees *must*
@@ -1150,9 +1150,8 @@ _outPlannerInfo(StringInfo str, PlannerInfo *node)
11501150
{
11511151
WRITE_NODE_TYPE("PLANNERINFO");
11521152

1153+
/* NB: this isn't a complete set of fields */
11531154
WRITE_NODE_FIELD(parse);
1154-
WRITE_NODE_FIELD(base_rel_list);
1155-
WRITE_NODE_FIELD(other_rel_list);
11561155
WRITE_NODE_FIELD(join_rel_list);
11571156
WRITE_NODE_FIELD(equi_key_list);
11581157
WRITE_NODE_FIELD(in_info_list);

‎src/backend/optimizer/path/allpaths.c‎

Lines changed: 48 additions & 12 deletions
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $PostgreSQL: pgsql/src/backend/optimizer/path/allpaths.c,v 1.131 2005/06/05 22:32:55 tgl Exp $
11+
* $PostgreSQL: pgsql/src/backend/optimizer/path/allpaths.c,v 1.132 2005/06/06 04:13:35 tgl Exp $
1212
*
1313
*-------------------------------------------------------------------------
1414
*/
@@ -88,9 +88,33 @@ make_one_rel(PlannerInfo *root)
8888
rel=make_fromexpr_rel(root,root->parse->jointree);
8989

9090
/*
91-
* The result should join all the query's base rels.
91+
* The result should join alland onlythe query's base rels.
9292
*/
93-
Assert(bms_num_members(rel->relids)==list_length(root->base_rel_list));
93+
#ifdefUSE_ASSERT_CHECKING
94+
{
95+
intnum_base_rels=0;
96+
Indexrti;
97+
98+
for (rti=1;rti<root->base_rel_array_size;rti++)
99+
{
100+
RelOptInfo*brel=root->base_rel_array[rti];
101+
102+
if (brel==NULL)
103+
continue;
104+
105+
Assert(brel->relid==rti);/* sanity check on array */
106+
107+
/* ignore RTEs that are "other rels" */
108+
if (brel->reloptkind!=RELOPT_BASEREL)
109+
continue;
110+
111+
Assert(bms_is_member(rti,rel->relids));
112+
num_base_rels++;
113+
}
114+
115+
Assert(bms_num_members(rel->relids)==num_base_rels);
116+
}
117+
#endif
94118

95119
returnrel;
96120
}
@@ -104,16 +128,29 @@ make_one_rel(PlannerInfo *root)
104128
staticvoid
105129
set_base_rel_pathlists(PlannerInfo*root)
106130
{
107-
ListCell*l;
131+
Indexrti;
108132

109-
foreach(l,root->base_rel_list)
133+
/*
134+
* Note: because we call expand_inherited_rtentry inside the loop,
135+
* it's quite possible for the base_rel_array to be enlarged while
136+
* the loop runs. Hence don't try to optimize the loop.
137+
*/
138+
for (rti=1;rti<root->base_rel_array_size;rti++)
110139
{
111-
RelOptInfo*rel= (RelOptInfo*)lfirst(l);
112-
Indexrti=rel->relid;
140+
RelOptInfo*rel=root->base_rel_array[rti];
113141
RangeTblEntry*rte;
114142
List*inheritlist;
115143

116-
Assert(rti>0);/* better be base rel */
144+
/* there may be empty slots corresponding to non-baserel RTEs */
145+
if (rel==NULL)
146+
continue;
147+
148+
Assert(rel->relid==rti);/* sanity check on array */
149+
150+
/* ignore RTEs that are "other rels" */
151+
if (rel->reloptkind!=RELOPT_BASEREL)
152+
continue;
153+
117154
rte=rt_fetch(rti,root->parse->rtable);
118155

119156
if (rel->rtekind==RTE_SUBQUERY)
@@ -246,10 +283,9 @@ set_inherited_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
246283
childOID=childrte->relid;
247284

248285
/*
249-
* Make a RelOptInfo for the child so we can do planning. Do NOT
250-
* attach the RelOptInfo to the query's base_rel_list, however,
251-
* since the child is not part of the main join tree. Instead,
252-
* the child RelOptInfo is added to other_rel_list.
286+
* Make a RelOptInfo for the child so we can do planning.
287+
* Mark it as an "other rel" since it will not be part of the
288+
* main join tree.
253289
*/
254290
childrel=build_other_rel(root,childRTindex);
255291

‎src/backend/optimizer/plan/planmain.c‎

Lines changed: 7 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -14,7 +14,7 @@
1414
*
1515
*
1616
* IDENTIFICATION
17-
* $PostgreSQL: pgsql/src/backend/optimizer/plan/planmain.c,v 1.82 2005/06/05 22:32:56 tgl Exp $
17+
* $PostgreSQL: pgsql/src/backend/optimizer/plan/planmain.c,v 1.83 2005/06/06 04:13:35 tgl Exp $
1818
*
1919
*-------------------------------------------------------------------------
2020
*/
@@ -106,12 +106,15 @@ query_planner(PlannerInfo *root, List *tlist, double tuple_fraction,
106106
&constant_quals);
107107

108108
/*
109-
* init planner lists to empty
109+
* Init planner lists to empty. We create the base_rel_array with a
110+
* size that will be sufficient if no pullups or inheritance additions
111+
* happen ... otherwise it will be enlarged as needed.
110112
*
111113
* NOTE: in_info_list was set up by subquery_planner, do not touch here
112114
*/
113-
root->base_rel_list=NIL;
114-
root->other_rel_list=NIL;
115+
root->base_rel_array_size=list_length(parse->rtable)+1;
116+
root->base_rel_array= (RelOptInfo**)
117+
palloc0(root->base_rel_array_size*sizeof(RelOptInfo*));
115118
root->join_rel_list=NIL;
116119
root->equi_key_list=NIL;
117120

‎src/backend/optimizer/util/relnode.c‎

Lines changed: 71 additions & 83 deletions
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $PostgreSQL: pgsql/src/backend/optimizer/util/relnode.c,v 1.67 2005/06/05 22:32:56 tgl Exp $
11+
* $PostgreSQL: pgsql/src/backend/optimizer/util/relnode.c,v 1.68 2005/06/06 04:13:36 tgl Exp $
1212
*
1313
*-------------------------------------------------------------------------
1414
*/
@@ -25,7 +25,8 @@
2525

2626
staticRelOptInfo*make_reloptinfo(PlannerInfo*root,intrelid,
2727
RelOptKindreloptkind);
28-
staticvoidbuild_joinrel_tlist(PlannerInfo*root,RelOptInfo*joinrel);
28+
staticvoidbuild_joinrel_tlist(PlannerInfo*root,RelOptInfo*joinrel,
29+
RelOptInfo*input_rel);
2930
staticList*build_joinrel_restrictlist(PlannerInfo*root,
3031
RelOptInfo*joinrel,
3132
RelOptInfo*outer_rel,
@@ -43,78 +44,60 @@ static void subbuild_joinrel_joinlist(RelOptInfo *joinrel,
4344
/*
4445
* build_base_rel
4546
* Construct a new base relation RelOptInfo, and put it in the query's
46-
*base_rel_list.
47+
*base_rel_array.
4748
*/
4849
void
4950
build_base_rel(PlannerInfo*root,intrelid)
5051
{
51-
ListCell*l;
52-
RelOptInfo*rel;
52+
Assert(relid>0);
5353

5454
/* Rel should not exist already */
55-
foreach(l,root->base_rel_list)
56-
{
57-
rel= (RelOptInfo*)lfirst(l);
58-
if (relid==rel->relid)
59-
elog(ERROR,"rel already exists");
60-
}
61-
62-
/* It should not exist as an "other" rel, either */
63-
foreach(l,root->other_rel_list)
64-
{
65-
rel= (RelOptInfo*)lfirst(l);
66-
if (relid==rel->relid)
67-
elog(ERROR,"rel already exists as \"other\" rel");
68-
}
55+
if (relid<root->base_rel_array_size&&
56+
root->base_rel_array[relid]!=NULL)
57+
elog(ERROR,"rel already exists");
6958

7059
/* No existing RelOptInfo for this base rel, so make a new one */
71-
rel=make_reloptinfo(root,relid,RELOPT_BASEREL);
72-
73-
/* and add it to the list */
74-
root->base_rel_list=lcons(rel,root->base_rel_list);
60+
(void)make_reloptinfo(root,relid,RELOPT_BASEREL);
7561
}
7662

7763
/*
7864
* build_other_rel
7965
* Returns relation entry corresponding to 'relid', creating a new one
8066
* if necessary. This is for 'other' relations, which are much like
81-
* base relations except that theylive ina differentlist.
67+
* base relations except that theyhavea differentRelOptKind.
8268
*/
8369
RelOptInfo*
8470
build_other_rel(PlannerInfo*root,intrelid)
8571
{
86-
ListCell*l;
8772
RelOptInfo*rel;
8873

74+
Assert(relid>0);
75+
8976
/* Already made? */
90-
foreach(l,root->other_rel_list)
77+
if (relid<root->base_rel_array_size)
9178
{
92-
rel= (RelOptInfo*)lfirst(l);
93-
if (relid==rel->relid)
79+
rel=root->base_rel_array[relid];
80+
if (rel)
81+
{
82+
/* it should not exist as a base rel */
83+
if (rel->reloptkind==RELOPT_BASEREL)
84+
elog(ERROR,"rel already exists as base rel");
85+
/* otherwise, A-OK */
9486
returnrel;
95-
}
96-
97-
/* It should not exist as a base rel */
98-
foreach(l,root->base_rel_list)
99-
{
100-
rel= (RelOptInfo*)lfirst(l);
101-
if (relid==rel->relid)
102-
elog(ERROR,"rel already exists as base rel");
87+
}
10388
}
10489

10590
/* No existing RelOptInfo for this other rel, so make a new one */
10691
/* presently, must be an inheritance child rel */
10792
rel=make_reloptinfo(root,relid,RELOPT_OTHER_CHILD_REL);
10893

109-
/* and add it to the list */
110-
root->other_rel_list=lcons(rel,root->other_rel_list);
111-
11294
returnrel;
11395
}
11496

11597
/*
11698
* make_reloptinfo
117-
* Construct a RelOptInfo for the specified rangetable index.
99+
* Construct a RelOptInfo for the specified rangetable index,
100+
* and enter it into base_rel_array.
118101
*
119102
* Common code for build_base_rel and build_other_rel.
120103
*/
@@ -172,31 +155,40 @@ make_reloptinfo(PlannerInfo *root, int relid, RelOptKind reloptkind)
172155
break;
173156
}
174157

158+
/* Add the finished struct to the base_rel_array */
159+
if (relid >=root->base_rel_array_size)
160+
{
161+
intoldsize=root->base_rel_array_size;
162+
intnewsize;
163+
164+
newsize=Max(oldsize*2,relid+1);
165+
root->base_rel_array= (RelOptInfo**)
166+
repalloc(root->base_rel_array,newsize*sizeof(RelOptInfo*));
167+
MemSet(root->base_rel_array+oldsize,0,
168+
(newsize-oldsize)*sizeof(RelOptInfo*));
169+
root->base_rel_array_size=newsize;
170+
}
171+
172+
root->base_rel_array[relid]=rel;
173+
175174
returnrel;
176175
}
177176

178177
/*
179178
* find_base_rel
180-
* Find a base or other relation entry, which must already exist
181-
* (since we'd have no idea which list to add it to).
179+
* Find a base or other relation entry, which must already exist.
182180
*/
183181
RelOptInfo*
184182
find_base_rel(PlannerInfo*root,intrelid)
185183
{
186-
ListCell*l;
187184
RelOptInfo*rel;
188185

189-
foreach(l,root->base_rel_list)
190-
{
191-
rel= (RelOptInfo*)lfirst(l);
192-
if (relid==rel->relid)
193-
returnrel;
194-
}
186+
Assert(relid>0);
195187

196-
foreach(l,root->other_rel_list)
188+
if (relid<root->base_rel_array_size)
197189
{
198-
rel=(RelOptInfo*)lfirst(l);
199-
if (relid==rel->relid)
190+
rel=root->base_rel_array[relid];
191+
if (rel)
200192
returnrel;
201193
}
202194

@@ -308,8 +300,13 @@ build_join_rel(PlannerInfo *root,
308300
* Create a new tlist containing just the vars that need to be output
309301
* from this join (ie, are needed for higher joinclauses or final
310302
* output).
303+
*
304+
* NOTE: the tlist order for a join rel will depend on which pair of
305+
* outer and inner rels we first try to build it from. But the
306+
* contents should be the same regardless.
311307
*/
312-
build_joinrel_tlist(root,joinrel);
308+
build_joinrel_tlist(root,joinrel,outer_rel);
309+
build_joinrel_tlist(root,joinrel,inner_rel);
313310

314311
/*
315312
* Construct restrict and join clause lists for the new joinrel. (The
@@ -344,48 +341,39 @@ build_join_rel(PlannerInfo *root,
344341
* Builds a join relation's target list.
345342
*
346343
* The join's targetlist includes all Vars of its member relations that
347-
* will still be needed above the join.
348-
*
349-
* In a former lifetime, this just merged the tlists of the two member
350-
* relations first presented. While we could still do that, working from
351-
* lists of Vars would mean doing a find_base_rel lookup for each Var.
352-
* It seems more efficient to scan the list of base rels and collect the
353-
* needed vars directly from there.
344+
* will still be needed above the join. This subroutine adds all such
345+
* Vars from the specified input rel's tlist to the join rel's tlist.
354346
*
355347
* We also compute the expected width of the join's output, making use
356348
* of data that was cached at the baserel level by set_rel_width().
357349
*/
358350
staticvoid
359-
build_joinrel_tlist(PlannerInfo*root,RelOptInfo*joinrel)
351+
build_joinrel_tlist(PlannerInfo*root,RelOptInfo*joinrel,
352+
RelOptInfo*input_rel)
360353
{
361354
Relidsrelids=joinrel->relids;
362-
ListCell*rels;
355+
ListCell*vars;
363356

364-
joinrel->reltargetlist=NIL;
365-
joinrel->width=0;
366-
367-
foreach(rels,root->base_rel_list)
357+
foreach(vars,input_rel->reltargetlist)
368358
{
369-
RelOptInfo*baserel= (RelOptInfo*)lfirst(rels);
370-
ListCell*vars;
359+
Var*var= (Var*)lfirst(vars);
360+
RelOptInfo*baserel;
361+
intndx;
362+
363+
/* We can't run into any child RowExprs here */
364+
Assert(IsA(var,Var));
371365

372-
if (!bms_is_member(baserel->relid,relids))
373-
continue;
366+
/* Get the Var's original base rel */
367+
baserel=find_base_rel(root,var->varno);
374368

375-
foreach(vars,baserel->reltargetlist)
369+
/* Is it still needed above this joinrel? */
370+
ndx=var->varattno-baserel->min_attr;
371+
if (bms_nonempty_difference(baserel->attr_needed[ndx],relids))
376372
{
377-
Var*var= (Var*)lfirst(vars);
378-
intndx=var->varattno-baserel->min_attr;
379-
380-
/* We can't run into any child RowExprs here */
381-
Assert(IsA(var,Var));
382-
383-
if (bms_nonempty_difference(baserel->attr_needed[ndx],relids))
384-
{
385-
joinrel->reltargetlist=lappend(joinrel->reltargetlist,var);
386-
Assert(baserel->attr_widths[ndx]>0);
387-
joinrel->width+=baserel->attr_widths[ndx];
388-
}
373+
/* Yup, add it to the output */
374+
joinrel->reltargetlist=lappend(joinrel->reltargetlist,var);
375+
Assert(baserel->attr_widths[ndx]>0);
376+
joinrel->width+=baserel->attr_widths[ndx];
389377
}
390378
}
391379
}

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