database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-11-21 00:42:43 +03:00
Code Activity

Remove dead code now that orindxpath.c is history.

Browse Source 
We don't need make_restrictinfo_from_bitmapqual() anymore at all.
generate_bitmap_or_paths() doesn't need to be exported, and we can
drop its rather klugy restriction_only flag.
This commit is contained in:
Tom Lane
2013-12-30 12:50:31 -05:00
parent f343a880d5
commit f7fbf4b0be
5 changed files with 8 additions and 247 deletions
Download Patch File Download Diff File Expand all files Collapse all files

187
src/backend/optimizer/util/restrictinfo.c
View File

@@ -15,7 +15,6 @@
#include "postgres.h"
#include "optimizer/clauses.h"
#include "optimizer/predtest.h"
#include "optimizer/restrictinfo.h"
#include "optimizer/var.h"
@@ -87,192 +86,6 @@ make_restrictinfo(Expr *clause,
nullable_relids);
}
/*
* make_restrictinfo_from_bitmapqual
*
* Given the bitmapqual Path structure for a bitmap indexscan, generate
* RestrictInfo node(s) equivalent to the condition represented by the
* indexclauses of the Path structure.
*
* The result is a List (effectively, implicit-AND representation) of
* RestrictInfos.
*
* The caller must pass is_pushed_down, but we assume outerjoin_delayed
* and pseudoconstant are false while outer_relids and nullable_relids
* are NULL (no other kind of qual should ever get into a bitmapqual).
*
* If include_predicates is true, we add any partial index predicates to
* the explicit index quals. When this is not true, we return a condition
* that might be weaker than the actual scan represents.
*
* To do this through the normal make_restrictinfo() API, callers would have
* to strip off the RestrictInfo nodes present in the indexclauses lists, and
* then make_restrictinfo() would have to build new ones. It's better to have
* a specialized routine to allow sharing of RestrictInfos.
*
* The qual manipulations here are much the same as in create_bitmap_subplan;
* keep the two routines in sync!
*/
List *
make_restrictinfo_from_bitmapqual(Path *bitmapqual,
bool is_pushed_down,
bool include_predicates)
{
List *result;
ListCell *l;
if (IsA(bitmapqual, BitmapAndPath))
{
BitmapAndPath *apath = (BitmapAndPath *) bitmapqual;
/*
* There may well be redundant quals among the subplans, since a
* top-level WHERE qual might have gotten used to form several
* different index quals. We don't try exceedingly hard to eliminate
* redundancies, but we do eliminate obvious duplicates by using
* list_concat_unique.
*/
result = NIL;
foreach(l, apath->bitmapquals)
{
List *sublist;
sublist = make_restrictinfo_from_bitmapqual((Path *) lfirst(l),
is_pushed_down,
include_predicates);
result = list_concat_unique(result, sublist);
}
}
else if (IsA(bitmapqual, BitmapOrPath))
{
BitmapOrPath *opath = (BitmapOrPath *) bitmapqual;
List *withris = NIL;
List *withoutris = NIL;
/*
* Here, we only detect qual-free subplans. A qual-free subplan would
* cause us to generate "... OR true ..." which we may as well reduce
* to just "true". We do not try to eliminate redundant subclauses
* because (a) it's not as likely as in the AND case, and (b) we might
* well be working with hundreds or even thousands of OR conditions,
* perhaps from a long IN list. The performance of list_append_unique
* would be unacceptable.
*/
foreach(l, opath->bitmapquals)
{
List *sublist;
sublist = make_restrictinfo_from_bitmapqual((Path *) lfirst(l),
is_pushed_down,
include_predicates);
if (sublist == NIL)
{
/*
* If we find a qual-less subscan, it represents a constant
* TRUE, and hence the OR result is also constant TRUE, so we
* can stop here.
*/
return NIL;
}
/*
* If the sublist contains multiple RestrictInfos, we create an
* AND subclause. If there's just one, we have to check if it's
* an OR clause, and if so flatten it to preserve AND/OR flatness
* of our output.
*
* We construct lists with and without sub-RestrictInfos, so as
* not to have to regenerate duplicate RestrictInfos below.
*/
if (list_length(sublist) > 1)
{
withris = lappend(withris, make_andclause(sublist));
sublist = get_actual_clauses(sublist);
withoutris = lappend(withoutris, make_andclause(sublist));
}
else
{
RestrictInfo *subri = (RestrictInfo *) linitial(sublist);
Assert(IsA(subri, RestrictInfo));
if (restriction_is_or_clause(subri))
{
BoolExpr *subor = (BoolExpr *) subri->orclause;
Assert(or_clause((Node *) subor));
withris = list_concat(withris,
list_copy(subor->args));
subor = (BoolExpr *) subri->clause;
Assert(or_clause((Node *) subor));
withoutris = list_concat(withoutris,
list_copy(subor->args));
}
else
{
withris = lappend(withris, subri);
withoutris = lappend(withoutris, subri->clause);
}
}
}
/*
* Avoid generating one-element ORs, which could happen due to
* redundancy elimination or ScalarArrayOpExpr quals.
*/
if (list_length(withris) <= 1)
result = withris;
else
{
/* Here's the magic part not available to outside callers */
result =
list_make1(make_restrictinfo_internal(make_orclause(withoutris),
make_orclause(withris),
is_pushed_down,
false,
false,
NULL,
NULL,
NULL));
}
}
else if (IsA(bitmapqual, IndexPath))
{
IndexPath *ipath = (IndexPath *) bitmapqual;
result = list_copy(ipath->indexclauses);
if (include_predicates && ipath->indexinfo->indpred != NIL)
{
foreach(l, ipath->indexinfo->indpred)
{
Expr *pred = (Expr *) lfirst(l);
/*
* We know that the index predicate must have been implied by
* the query condition as a whole, but it may or may not be
* implied by the conditions that got pushed into the
* bitmapqual. Avoid generating redundant conditions.
*/
if (!predicate_implied_by(list_make1(pred), result))
result = lappend(result,
make_restrictinfo(pred,
is_pushed_down,
false,
false,
NULL,
NULL,
NULL));
}
}
}
else
{
elog(ERROR, "unrecognized node type: %d", nodeTag(bitmapqual));
result = NIL; /* keep compiler quiet */
}
return result;
}
/*
* make_restrictinfos_from_actual_clauses
*