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1. Enable to have different _CPU_PAGE_WEIGHT_ for heap and index. 

2. PageWeights are variables now.
3. Fixed using ceil((double)selec*indextuples) as estimation
for expected heap pages: ceil((double)selec*relpages) now.
This commit is contained in:
Vadim B. Mikheev 1997-04-09 02:13:41 +00:00
parent fa2629b7ea
commit 610d0d00ed
1 changed files with 20 additions and 16 deletions
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36
src/backend/optimizer/path/costsize.c
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@ -7,7 +7,7 @@
* *
* *
* IDENTIFICATION * IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/path/costsize.c,v 1.13 1997/02/14 04:15:35 momjian Exp $ * $Header: /cvsroot/pgsql/src/backend/optimizer/path/costsize.c,v 1.14 1997/04/09 02:13:41 vadim Exp $
* *
*------------------------------------------------------------------------- *-------------------------------------------------------------------------
*/ */
@ -52,6 +52,9 @@ bool _enable_nestloop_ = true;
bool _enable_mergesort_ = true; bool _enable_mergesort_ = true;
bool _enable_hashjoin_ = true; bool _enable_hashjoin_ = true;
Cost _cpu_page_wight_ = _CPU_PAGE_WEIGHT_;
Cost _cpu_index_page_wight_ = _CPU_INDEX_PAGE_WEIGHT_;
/* /*
* cost_seqscan-- * cost_seqscan--
* Determines and returns the cost of scanning a relation sequentially. * Determines and returns the cost of scanning a relation sequentially.
@ -87,7 +90,7 @@ cost_seqscan(int relid, int relpages, int reltuples)
temp += _TEMP_SCAN_COST_; temp += _TEMP_SCAN_COST_;
} else { } else {
temp += relpages; temp += relpages;
temp += _CPU_PAGE_WEIGHT_ * reltuples; temp += _cpu_page_wight_ * reltuples;
} }
Assert(temp >= 0); Assert(temp >= 0);
return(temp); return(temp);
@ -124,9 +127,9 @@ cost_index(Oid indexid,
bool is_injoin) bool is_injoin)
{ {
Cost temp; Cost temp;
Cost temp2; double temp2;
temp = temp2 = (Cost) 0; temp = (Cost) 0;
if (!_enable_indexscan_ && !is_injoin) if (!_enable_indexscan_ && !is_injoin)
temp += _disable_cost_; temp += _disable_cost_;
@ -134,16 +137,17 @@ cost_index(Oid indexid,
/* expected index relation pages */ /* expected index relation pages */
temp += expected_indexpages; temp += expected_indexpages;
/* about one base relation page */ /* expected base relation pages */
temp += Min(relpages,(int)ceil((double)selec*indextuples)); temp2 = ( reltuples == 0 ) ? (double)0 : (double)relpages/reltuples;
temp2 = temp2 * (double)selec * indextuples;
temp += Min (relpages, (int)ceil (temp2));
/* /* per index tuples */
* per index tuple temp = temp + (_cpu_index_page_wight_ * selec * indextuples);
*/
temp2 += selec * indextuples; /* per heap tuples */
temp2 += selec * reltuples; temp = temp + (_cpu_page_wight_ * selec * reltuples);
temp = temp + (_CPU_PAGE_WEIGHT_ * temp2);
Assert(temp >= 0); Assert(temp >= 0);
return(temp); return(temp);
} }
@ -186,7 +190,7 @@ cost_sort(List *keys, int tuples, int width, bool noread)
/* /*
* could be base_log(pages, NBuffers), but we are only doing 2-way merges * could be base_log(pages, NBuffers), but we are only doing 2-way merges
*/ */
temp += _CPU_PAGE_WEIGHT_ * temp += _cpu_page_wight_ *
numTuples * base_log((double)pages,(double)2.0); numTuples * base_log((double)pages,(double)2.0);
if( !noread ) if( !noread )
@ -210,7 +214,7 @@ cost_result(int tuples, int width)
{ {
Cost temp =0; Cost temp =0;
temp = temp + page_size(tuples,width); temp = temp + page_size(tuples,width);
temp = temp + _CPU_PAGE_WEIGHT_ * tuples; temp = temp + _cpu_page_wight_ * tuples;
Assert(temp >= 0); Assert(temp >= 0);
return(temp); return(temp);
} }
@ -279,7 +283,7 @@ cost_mergesort(Cost outercost,
temp += innercost; temp += innercost;
temp += cost_sort(outersortkeys,outersize,outerwidth,false); temp += cost_sort(outersortkeys,outersize,outerwidth,false);
temp += cost_sort(innersortkeys,innersize,innerwidth,false); temp += cost_sort(innersortkeys,innersize,innerwidth,false);
temp += _CPU_PAGE_WEIGHT_ * (outersize + innersize); temp += _cpu_page_wight_ * (outersize + innersize);
Assert(temp >= 0); Assert(temp >= 0);
return(temp); return(temp);
@ -327,7 +331,7 @@ cost_hashjoin(Cost outercost,
*/ */
temp += outercost + (nrun + 1); temp += outercost + (nrun + 1);
temp += _CPU_PAGE_WEIGHT_ * (outersize + nrun * innersize); temp += _cpu_page_wight_ * (outersize + nrun * innersize);
Assert(temp >= 0); Assert(temp >= 0);
return(temp); return(temp);