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Remove reltarget_has_non_vars flag.

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Commit b12fd41c6 added a "reltarget_has_non_vars" field to RelOptInfo,
but failed to maintain it accurately.  Since its only purpose was to skip
calls to has_parallel_hazard() in the simple case where a rel's targetlist
is all Vars, and that call is really pretty cheap in that case anyway, it
seems like this is just a case of premature optimization.  Let's drop the
flag and do the calls unconditionally until it's proven that we need more
smarts here.
This commit is contained in:
Tom Lane 2016-06-10 16:20:03 -04:00
parent 2f153ddfdd
commit 3303ea1a32
5 changed files with 4 additions and 15 deletions
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1
src/backend/nodes/outfuncs.c
View File

@ -2083,7 +2083,6 @@ _outRelOptInfo(StringInfo str, const RelOptInfo *node)
WRITE_BOOL_FIELD(consider_param_startup);
WRITE_BOOL_FIELD(consider_parallel);
WRITE_NODE_FIELD(reltarget);
WRITE_BOOL_FIELD(reltarget_has_non_vars);
WRITE_NODE_FIELD(pathlist);
WRITE_NODE_FIELD(ppilist);
WRITE_NODE_FIELD(partial_pathlist);

9
src/backend/optimizer/path/allpaths.c
View File

@ -613,12 +613,10 @@ set_rel_consider_parallel(PlannerInfo *root, RelOptInfo *rel,
return;
/*
* If the relation's outputs are not parallel-safe, we must give up. In
* the common case where the relation only outputs Vars, this check is
* very cheap; otherwise, we have to do more work.
* Likewise, if the relation's outputs are not parallel-safe, give up.
* (Usually, they're just Vars, but sometimes they're not.)
*/
if (rel->reltarget_has_non_vars &&
has_parallel_hazard((Node *) rel->reltarget->exprs, false))
if (has_parallel_hazard((Node *) rel->reltarget->exprs, false))
return;
/* We have a winner. */
@ -984,7 +982,6 @@ set_append_rel_size(PlannerInfo *root, RelOptInfo *rel,
adjust_appendrel_attrs(root,
(Node *) rel->reltarget->exprs,
appinfo);
childrel->reltarget_has_non_vars = rel->reltarget_has_non_vars;
/*
* We have to make child entries in the EquivalenceClass data

2
src/backend/optimizer/util/placeholder.c
View File

@ -393,7 +393,6 @@ add_placeholders_to_base_rels(PlannerInfo *root)
rel->reltarget->exprs = lappend(rel->reltarget->exprs,
copyObject(phinfo->ph_var));
rel->reltarget_has_non_vars = true;
/* reltarget's cost and width fields will be updated later */
}
}
@ -428,7 +427,6 @@ add_placeholders_to_joinrel(PlannerInfo *root, RelOptInfo *joinrel,
/* Yup, add it to the output */
joinrel->reltarget->exprs = lappend(joinrel->reltarget->exprs,
phinfo->ph_var);
joinrel->reltarget_has_non_vars = true;
joinrel->reltarget->width += phinfo->ph_width;
/*

5
src/backend/optimizer/util/relnode.c
View File

@ -109,7 +109,6 @@ build_simple_rel(PlannerInfo *root, int relid, RelOptKind reloptkind)
rel->consider_parallel = false; /* might get changed later */
rel->rel_parallel_workers = -1; /* set up in GetRelationInfo */
rel->reltarget = create_empty_pathtarget();
rel->reltarget_has_non_vars = false;
rel->pathlist = NIL;
rel->ppilist = NIL;
rel->partial_pathlist = NIL;
@ -397,7 +396,6 @@ build_join_rel(PlannerInfo *root,
joinrel->consider_param_startup = false;
joinrel->consider_parallel = false;
joinrel->reltarget = create_empty_pathtarget();
joinrel->reltarget_has_non_vars = false;
joinrel->pathlist = NIL;
joinrel->ppilist = NIL;
joinrel->partial_pathlist = NIL;
@ -520,8 +518,7 @@ build_join_rel(PlannerInfo *root,
*/
if (inner_rel->consider_parallel && outer_rel->consider_parallel &&
!has_parallel_hazard((Node *) restrictlist, false) &&
!(joinrel->reltarget_has_non_vars &&
has_parallel_hazard((Node *) joinrel->reltarget->exprs, false)))
!has_parallel_hazard((Node *) joinrel->reltarget->exprs, false))
joinrel->consider_parallel = true;
/*

2
src/include/nodes/relation.h
View File

@ -490,8 +490,6 @@ typedef struct RelOptInfo
/* default result targetlist for Paths scanning this relation */
struct PathTarget *reltarget; /* list of Vars/Exprs, cost, width */
bool reltarget_has_non_vars; /* true if any expression in
* PathTarget is a non-Var */
/* materialization information */
List *pathlist; /* Path structures */