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postgresql/src/include/optimizer/cost.h

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Postgres95 1.01 Distribution - Virgin Sources
1996-07-09 08:22:35 +02:00
/*-------------------------------------------------------------------------
*
Change my-function-name-- to my_function_name, and optimizer renames.
1999-02-14 00:22:53 +01:00
* cost.h
Massive commit to run PGINDENT on all *.c and *.h files.
1997-09-07 07:04:48 +02:00
* prototypes for costsize.c and clausesel.c.
Postgres95 1.01 Distribution - Virgin Sources
1996-07-09 08:22:35 +02:00
*
*
* Copyright (c) 1994, Regents of the University of California
*
Revise generation of hashjoin paths: generate one path per hashjoinable clause, not one path for a randomly-chosen element of each set of clauses with the same join operator. That is, if you wrote SELECT ... WHERE t1.f1 = t2.f2 and t1.f3 = t2.f4, and both '=' ops were the same opcode (say, all four fields are int4), then the system would either consider hashing on f1=f2 or on f3=f4, but it would *not* consider both possibilities. Boo hiss. Also, revise estimation of hashjoin costs to include a penalty when the inner join var has a high disbursion --- ie, the most common value is pretty common. This tends to lead to badly skewed hash bucket occupancy and way more comparisons than you'd expect on average. I imagine that the cost calculation still needs tweaking, but at least it generates a more reasonable plan than before on George Young's example.
1999-08-06 06:00:17 +02:00
* $Id: cost.h,v 1.23 1999/08/06 04:00:13 tgl Exp $
Postgres95 1.01 Distribution - Virgin Sources
1996-07-09 08:22:35 +02:00
*
*-------------------------------------------------------------------------
*/
#ifndef COST_H
#define COST_H
Cleanup up include files.
1997-11-26 02:14:33 +01:00
#include "nodes/relation.h"
Clean up #include in /include directory. Add scripts for checking includes.
1999-07-15 17:21:54 +02:00
/* defaults for function attributes used for expensive function calculations */
#define BYTE_PCT 100
#define PERBYTE_CPU 0
#define PERCALL_CPU 0
#define OUTIN_RATIO 100
Postgres95 1.01 Distribution - Virgin Sources
1996-07-09 08:22:35 +02:00
/*
Change my-function-name-- to my_function_name, and optimizer renames.
1999-02-14 00:22:53 +01:00
* prototypes for costsize.c
Massive commit to run PGINDENT on all *.c and *.h files.
1997-09-07 07:04:48 +02:00
* routines to compute costs and sizes
*/
Another PGINDENT run that changes variable indenting and case label indenting. Also static variable indenting.
1997-09-08 04:41:22 +02:00
extern bool _enable_seqscan_;
extern bool _enable_indexscan_;
extern bool _enable_sort_;
extern bool _enable_nestloop_;
MergeSort was sometimes called mergejoin and was confusing. Now it is now only mergejoin.
1998-08-04 18:44:31 +02:00
extern bool _enable_mergejoin_;
Another PGINDENT run that changes variable indenting and case label indenting. Also static variable indenting.
1997-09-08 04:41:22 +02:00
extern bool _enable_hashjoin_;
Postgres95 1.01 Distribution - Virgin Sources
1996-07-09 08:22:35 +02:00
Another PGINDENT run that changes variable indenting and case label indenting. Also static variable indenting.
1997-09-08 04:41:22 +02:00
extern Cost cost_seqscan(int relid, int relpages, int reltuples);
OK, folks, here is the pgindent output.
1998-09-01 06:40:42 +02:00
extern Cost cost_index(Oid indexid, int expected_indexpages, Cost selec,
Massive commit to run PGINDENT on all *.c and *.h files.
1997-09-07 07:04:48 +02:00
int relpages, int reltuples, int indexpages,
int indextuples, bool is_injoin);
Clean up cost_sort some more: most callers were double-counting the cost of reading the source data.
1999-05-01 21:47:42 +02:00
extern Cost cost_sort(List *pathkeys, int tuples, int width);
OK, folks, here is the pgindent output.
1998-09-01 06:40:42 +02:00
extern Cost cost_nestloop(Cost outercost, Cost innercost, int outertuples,
Massive commit to run PGINDENT on all *.c and *.h files.
1997-09-07 07:04:48 +02:00
int innertuples, int outerpages, bool is_indexjoin);
OK, folks, here is the pgindent output.
1998-09-01 06:40:42 +02:00
extern Cost cost_mergejoin(Cost outercost, Cost innercost,
Used modified version of indent that understands over 100 typedefs.
1997-09-08 23:56:23 +02:00
List *outersortkeys, List *innersortkeys,
Massive commit to run PGINDENT on all *.c and *.h files.
1997-09-07 07:04:48 +02:00
int outersize, int innersize, int outerwidth, int innerwidth);
Revise generation of hashjoin paths: generate one path per hashjoinable clause, not one path for a randomly-chosen element of each set of clauses with the same join operator. That is, if you wrote SELECT ... WHERE t1.f1 = t2.f2 and t1.f3 = t2.f4, and both '=' ops were the same opcode (say, all four fields are int4), then the system would either consider hashing on f1=f2 or on f3=f4, but it would *not* consider both possibilities. Boo hiss. Also, revise estimation of hashjoin costs to include a penalty when the inner join var has a high disbursion --- ie, the most common value is pretty common. This tends to lead to badly skewed hash bucket occupancy and way more comparisons than you'd expect on average. I imagine that the cost calculation still needs tweaking, but at least it generates a more reasonable plan than before on George Young's example.
1999-08-06 06:00:17 +02:00
extern Cost cost_hashjoin(Cost outercost, Cost innercost,
int outersize, int innersize,
int outerwidth, int innerwidth,
Cost innerdisbursion);
Another pgindent run. Sorry folks.
1999-05-26 00:43:53 +02:00
extern int compute_rel_size(RelOptInfo *rel);
extern int compute_rel_width(RelOptInfo *rel);
Optimizer cleanup.
1999-02-12 18:25:05 +01:00
extern int compute_joinrel_size(JoinPath *joinpath);
Another PGINDENT run that changes variable indenting and case label indenting. Also static variable indenting.
1997-09-08 04:41:22 +02:00
extern int page_size(int tuples, int width);
Postgres95 1.01 Distribution - Virgin Sources
1996-07-09 08:22:35 +02:00
/*
Change my-function-name-- to my_function_name, and optimizer renames.
1999-02-14 00:22:53 +01:00
* prototypes for fuctions in clausesel.h
Massive commit to run PGINDENT on all *.c and *.h files.
1997-09-07 07:04:48 +02:00
* routines to compute clause selectivities
Postgres95 1.01 Distribution - Virgin Sources
1996-07-09 08:22:35 +02:00
*/
Optimizer rename ClauseInfo -> RestrictInfo. Update optimizer README.
1999-02-03 21:15:53 +01:00
extern void set_clause_selectivities(List *restrictinfo_list, Cost new_selectivity);
extern Cost product_selec(List *restrictinfo_list);
Used modified version of indent that understands over 100 typedefs.
1997-09-08 23:56:23 +02:00
extern void set_rest_relselec(Query *root, List *rel_list);
Optimizer rename ClauseInfo -> RestrictInfo. Update optimizer README.
1999-02-03 21:15:53 +01:00
extern void set_rest_selec(Query *root, List *restrictinfo_list);
Clean up messy clause-selectivity code in clausesel.c; repair bug 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.)
1999-07-25 01:21:14 +02:00
extern Cost compute_clause_selec(Query *root, Node *clause);
Postgres95 1.01 Distribution - Virgin Sources
1996-07-09 08:22:35 +02:00
OK, folks, here is the pgindent output.
1998-09-01 06:40:42 +02:00
#endif /* COST_H */
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