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The attached patch fixes some spelling mistakes, makes the

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comments on one of the optimizer functions a lot more
clear, adds a summary of the recent KSQO discussion to the
comments in the code, adds regression tests for the bug with
sequence state Tom fixed recently and another reg. test, and
removes some PostQuel legacy stuff: ExecAppend -> ExecInsert,
ExecRetrieve -> ExecSelect, etc.

Error messages remain unchanged until a vote.

Neil Conway
This commit is contained in:
Bruce Momjian
2002-06-26 21:58:56 +00:00
parent 893fe4919d
commit 73ad6ca96c
9 changed files with 83 additions and 56 deletions
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12
src/backend/optimizer/path/costsize.c
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@@ -42,7 +42,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/path/costsize.c,v 1.87 2002/06/25 17:58:10 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/path/costsize.c,v 1.88 2002/06/26 21:58:56 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@@ -154,11 +154,11 @@ cost_seqscan(Path *path, Query *root,
*
* Given a guesstimated cache size, we estimate the actual I/O cost per page
* with the entirely ad-hoc equations:
* for rel_size <= effective_cache_size:
* 1 + (random_page_cost/2-1) * (rel_size/effective_cache_size) ** 2
* for rel_size >= effective_cache_size:
* random_page_cost * (1 - (effective_cache_size/rel_size)/2)
* These give the right asymptotic behavior (=> 1.0 as rel_size becomes
* if relpages >= effective_cache_size:
* random_page_cost * (1 - (effective_cache_size/relpages)/2)
* if relpages < effective_cache_size:
* 1 + (random_page_cost/2-1) * (relpages/effective_cache_size) ** 2
* These give the right asymptotic behavior (=> 1.0 as relpages becomes
* small, => random_page_cost as it becomes large) and meet in the middle
* with the estimate that the cache is about 50% effective for a relation
* of the same size as effective_cache_size. (XXX this is probably all

17
src/backend/optimizer/prep/_deadcode/prepkeyset.c
View File

@@ -1,7 +1,7 @@
/*-------------------------------------------------------------------------
*
* prepkeyset.c
* Special preperation for keyset queries.
* Special preparation for keyset queries (KSQO).
*
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
@@ -14,12 +14,6 @@
#include "postgres.h"
#include "optimizer/planmain.h"
/*
* Node_Copy
* a macro to simplify calling of copyObject on the specified field
*/
#define Node_Copy(from, newnode, field) newnode->field = copyObject(from->field)
bool _use_keyset_query_optimizer = FALSE;
#ifdef ENABLE_KEY_SET_QUERY
@@ -55,13 +49,20 @@ static int TotalExpr;
* a HAVING, or a GROUP BY. It must be a single table and have KSQO
* set to 'on'.
*
* The primary use of this transformation is to avoid the exponrntial
* The primary use of this transformation is to avoid the exponential
* memory consumption of cnfify() and to make use of index access
* methods.
*
* daveh@insightdist.com 1998-08-31
*
* May want to also prune out duplicate terms.
*
* XXX: this code is currently not compiled because it has not been
* updated to work with the re-implementation of UNION/INTERSECT/EXCEPT
* in PostgreSQL 7.1. However, it is of questionable value in any
* case, because it changes the semantics of the original query:
* UNION will add an implicit SELECT DISTINCT, which might change
* the results that are returned.
**********************************************************************/
void
transformKeySetQuery(Query *origNode)