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MergeSort was sometimes called mergejoin and was confusing. Now

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it is now only mergejoin.
This commit is contained in:
Bruce Momjian
1998-08-04 16:44:31 +00:00
parent 7db9ea5c1e
commit d9be0ff432
23 changed files with 117 additions and 116 deletions
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34
src/backend/optimizer/path/joinpath.c
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@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/path/joinpath.c,v 1.7 1998/07/18 04:22:32 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/path/joinpath.c,v 1.8 1998/08/04 16:44:07 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -27,7 +27,7 @@
#include "optimizer/pathnode.h"
#include "optimizer/keys.h"
#include "optimizer/cost.h" /* for _enable_{hashjoin,
* _enable_mergesort} */
* _enable_mergejoin} */
static Path *best_innerjoin(List *join_paths, List *outer_relid);
static List *
@ -98,7 +98,7 @@ find_all_join_paths(Query *root, List *joinrels)
bestinnerjoin = best_innerjoin(innerrel->innerjoin,
outerrel->relids);
if (_enable_mergesort_)
if (_enable_mergejoin_)
{
mergeinfo_list =
group_clauses_by_order(joinrel->clauseinfo,
@ -116,7 +116,7 @@ find_all_join_paths(Query *root, List *joinrels)
joinrel->relids = intAppend(outerrelids, innerrelids);
/*
* 1. Consider mergesort paths where both relations must be
* 1. Consider mergejoin paths where both relations must be
* explicitly sorted.
*/
pathlist = sort_inner_and_outer(joinrel, outerrel,
@ -125,7 +125,7 @@ find_all_join_paths(Query *root, List *joinrels)
/*
* 2. Consider paths where the outer relation need not be
* explicitly sorted. This may include either nestloops and
* mergesorts where the outer path is already ordered.
* mergejoins where the outer path is already ordered.
*/
pathlist =
add_pathlist(joinrel, pathlist,
@ -139,7 +139,7 @@ find_all_join_paths(Query *root, List *joinrels)
/*
* 3. Consider paths where the inner relation need not be
* explicitly sorted. This may include nestloops and mergesorts
* explicitly sorted. This may include nestloops and mergejoins
* the actual nestloop nodes were constructed in
* (match-unsorted-outer).
*/
@ -226,16 +226,16 @@ best_innerjoin(List *join_paths, List *outer_relids)
/*
* sort-inner-and-outer--
* Create mergesort join paths by explicitly sorting both the outer and
* Create mergejoin join paths by explicitly sorting both the outer and
* inner join relations on each available merge ordering.
*
* 'joinrel' is the join relation
* 'outerrel' is the outer join relation
* 'innerrel' is the inner join relation
* 'mergeinfo-list' is a list of nodes containing info on(mergesortable)
* 'mergeinfo-list' is a list of nodes containing info on(mergejoinable)
* clauses for joining the relations
*
* Returns a list of mergesort paths.
* Returns a list of mergejoin paths.
*/
static List *
sort_inner_and_outer(RelOptInfo *joinrel,
@ -270,7 +270,7 @@ sort_inner_and_outer(RelOptInfo *joinrel,
xmergeinfo->jmethod.clauses);
temp_node =
create_mergesort_path(joinrel,
create_mergejoin_path(joinrel,
outerrel->size,
innerrel->size,
outerrel->width,
@ -292,12 +292,12 @@ sort_inner_and_outer(RelOptInfo *joinrel,
* match-unsorted-outer--
* Creates possible join paths for processing a single join relation
* 'joinrel' by employing either iterative substitution or
* mergesorting on each of its possible outer paths(assuming that the
* mergejoining on each of its possible outer paths(assuming that the
* outer relation need not be explicitly sorted).
*
* 1. The inner path is the cheapest available inner path.
* 2. Mergesort wherever possible. Mergesorts are considered if there
* are mergesortable join clauses between the outer and inner join
* 2. Mergejoin wherever possible. Mergejoin are considered if there
* are mergejoinable join clauses between the outer and inner join
* relations such that the outer path is keyed on the variables
* appearing in the clauses. The corresponding inner merge path is
* either a path whose keys match those of the outer path(if such a
@ -310,7 +310,7 @@ sort_inner_and_outer(RelOptInfo *joinrel,
* 'outerpath-list' is the list of possible outer paths
* 'cheapest-inner' is the cheapest inner path
* 'best-innerjoin' is the best inner index path(if any)
* 'mergeinfo-list' is a list of nodes containing info on mergesortable
* 'mergeinfo-list' is a list of nodes containing info on mergejoinable
* clauses
*
* Returns a list of possible join path nodes.
@ -424,7 +424,7 @@ match_unsorted_outer(RelOptInfo *joinrel,
mergeinnerpath = cheapest_inner;
temp_node =
lcons(create_mergesort_path(joinrel,
lcons(create_mergejoin_path(joinrel,
outerrel->size,
innerrel->size,
outerrel->width,
@ -463,7 +463,7 @@ match_unsorted_outer(RelOptInfo *joinrel,
* 'outerrel' is the outer join relation
* 'innerrel' is the inner join relation
* 'innerpath-list' is the list of possible inner join paths
* 'mergeinfo-list' is a list of nodes containing info on mergesortable
* 'mergeinfo-list' is a list of nodes containing info on mergejoinable
* clauses
*
* Returns a list of possible merge paths.
@ -542,7 +542,7 @@ match_unsorted_inner(RelOptInfo *joinrel,
clauses);
temp_node =
lcons(create_mergesort_path(joinrel,
lcons(create_mergejoin_path(joinrel,
outerrel->size,
innerrel->size,
outerrel->width,