/*
* bitmap_match: match function to use with bitmap_hash
*/
int
bitmap_match(const void *key1, const void *key2, size_t keysize)
{
ASSERT(keysize == sizeof(struct bms *));
return !bms_equal((const struct bms*) key1, (const struct bms*) key2);
}
/*
* bitmap_match: match function to use with bitmap_hash
*/
int
bitmap_match(const void *key1, const void *key2, Size keysize)
{
Assert(keysize == sizeof(Bitmapset *));
return !bms_equal(*((const Bitmapset *const *) key1),
*((const Bitmapset *const *) key2));
}
/*
* make_join_rel
* Find or create a join RelOptInfo that represents the join of
* the two given rels, and add to it path information for paths
* created with the two rels as outer and inner rel.
* (The join rel may already contain paths generated from other
* pairs of rels that add up to the same set of base rels.)
*
* NB: will return NULL if attempted join is not valid. This can happen
* when working with outer joins, or with IN or EXISTS clauses that have been
* turned into joins.
*/
RelOptInfo *
make_join_rel(PlannerInfo *root, RelOptInfo *rel1, RelOptInfo *rel2)
{
Relids joinrelids;
SpecialJoinInfo *sjinfo;
bool reversed;
SpecialJoinInfo sjinfo_data;
RelOptInfo *joinrel;
List *restrictlist;
/* We should never try to join two overlapping sets of rels. */
Assert(!bms_overlap(rel1->relids, rel2->relids));
/* Construct Relids set that identifies the joinrel. */
joinrelids = bms_union(rel1->relids, rel2->relids);
/* Check validity and determine join type. */
if (!join_is_legal(root, rel1, rel2, joinrelids,
&sjinfo, &reversed))
{
/* invalid join path */
bms_free(joinrelids);
return NULL;
}
/* Swap rels if needed to match the join info. */
if (reversed)
{
RelOptInfo *trel = rel1;
rel1 = rel2;
rel2 = trel;
}
/*
* If it's a plain inner join, then we won't have found anything in
* join_info_list. Make up a SpecialJoinInfo so that selectivity
* estimation functions will know what's being joined.
*/
if (sjinfo == NULL)
{
sjinfo = &sjinfo_data;
sjinfo->type = T_SpecialJoinInfo;
sjinfo->min_lefthand = rel1->relids;
sjinfo->min_righthand = rel2->relids;
sjinfo->syn_lefthand = rel1->relids;
sjinfo->syn_righthand = rel2->relids;
sjinfo->jointype = JOIN_INNER;
/* we don't bother trying to make the remaining fields valid */
sjinfo->lhs_strict = false;
sjinfo->delay_upper_joins = false;
sjinfo->semi_can_btree = false;
sjinfo->semi_can_hash = false;
sjinfo->semi_operators = NIL;
sjinfo->semi_rhs_exprs = NIL;
}
/*
* Find or build the join RelOptInfo, and compute the restrictlist that
* goes with this particular joining.
*/
joinrel = build_join_rel(root, joinrelids, rel1, rel2, sjinfo,
&restrictlist);
/* !!! START: HERE IS THE PART WHICH ADDED FOR PG_HINT_PLAN !!! */
{
RowsHint *rows_hint = NULL;
int i;
RowsHint *justforme = NULL;
RowsHint *domultiply = NULL;
/* Search for applicable rows hint for this join node */
for (i = 0; i < current_hint->num_hints[HINT_TYPE_ROWS]; i++)
{
rows_hint = current_hint->rows_hints[i];
/*
* Skip this rows_hint if it is invalid from the first or it
* doesn't target any join rels.
*/
if (!rows_hint->joinrelids ||
rows_hint->base.state == HINT_STATE_ERROR)
continue;
if (bms_equal(joinrelids, rows_hint->joinrelids))
{
/*
* This joinrel is just the target of this rows_hint, so tweak
* rows estimation according to the hint.
*/
justforme = rows_hint;
}
else if (!(bms_is_subset(rows_hint->joinrelids, rel1->relids) ||
bms_is_subset(rows_hint->joinrelids, rel2->relids)) &&
bms_is_subset(rows_hint->joinrelids, joinrelids) &&
rows_hint->value_type == RVT_MULTI)
{
/*
* If the rows_hint's target relids is not a subset of both of
* component rels and is a subset of this joinrel, ths hint's
* targets spread over both component rels. This menas that
* this hint has been never applied so far and this joinrel is
* the first (and only) chance to fire in current join tree.
* Only the multiplication hint has the cumulative nature so we
* apply only RVT_MULTI in this way.
*/
domultiply = rows_hint;
}
}
if (justforme)
{
/*
* If a hint just for me is found, no other adjust method is
* useles, but this cannot be more than twice becuase this joinrel
* is already adjusted by this hint.
*/
if (justforme->base.state == HINT_STATE_NOTUSED)
joinrel->rows = adjust_rows(joinrel->rows, justforme);
}
else
{
if (domultiply)
{
/*
* If we have multiple routes up to this joinrel which are not
* applicable this hint, this multiply hint will applied more
* than twice. But there's no means to know of that,
* re-estimate the row number of this joinrel always just
* before applying the hint. This is a bit different from
* normal planner behavior but it doesn't harm so much.
*/
set_joinrel_size_estimates(root, joinrel, rel1, rel2, sjinfo,
restrictlist);
joinrel->rows = adjust_rows(joinrel->rows, domultiply);
}
}
}
/* !!! END: HERE IS THE PART WHICH ADDED FOR PG_HINT_PLAN !!! */
/*
* If we've already proven this join is empty, we needn't consider any
* more paths for it.
*/
if (is_dummy_rel(joinrel))
{
bms_free(joinrelids);
return joinrel;
}
/*
* Consider paths using each rel as both outer and inner. Depending on
* the join type, a provably empty outer or inner rel might mean the join
* is provably empty too; in which case throw away any previously computed
* paths and mark the join as dummy. (We do it this way since it's
* conceivable that dummy-ness of a multi-element join might only be
* noticeable for certain construction paths.)
*
* Also, a provably constant-false join restriction typically means that
* we can skip evaluating one or both sides of the join. We do this by
* marking the appropriate rel as dummy. For outer joins, a
* constant-false restriction that is pushed down still means the whole
* join is dummy, while a non-pushed-down one means that no inner rows
* will join so we can treat the inner rel as dummy.
*
* We need only consider the jointypes that appear in join_info_list, plus
* JOIN_INNER.
*/
switch (sjinfo->jointype)
{
case JOIN_INNER:
if (is_dummy_rel(rel1) || is_dummy_rel(rel2) ||
restriction_is_constant_false(restrictlist, false))
{
mark_dummy_rel(joinrel);
break;
}
add_paths_to_joinrel(root, joinrel, rel1, rel2,
JOIN_INNER, sjinfo,
restrictlist);
add_paths_to_joinrel(root, joinrel, rel2, rel1,
JOIN_INNER, sjinfo,
restrictlist);
break;
case JOIN_LEFT:
if (is_dummy_rel(rel1) ||
restriction_is_constant_false(restrictlist, true))
{
mark_dummy_rel(joinrel);
break;
}
if (restriction_is_constant_false(restrictlist, false) &&
bms_is_subset(rel2->relids, sjinfo->syn_righthand))
mark_dummy_rel(rel2);
add_paths_to_joinrel(root, joinrel, rel1, rel2,
JOIN_LEFT, sjinfo,
restrictlist);
add_paths_to_joinrel(root, joinrel, rel2, rel1,
JOIN_RIGHT, sjinfo,
restrictlist);
break;
case JOIN_FULL:
if ((is_dummy_rel(rel1) && is_dummy_rel(rel2)) ||
restriction_is_constant_false(restrictlist, true))
{
mark_dummy_rel(joinrel);
break;
}
add_paths_to_joinrel(root, joinrel, rel1, rel2,
JOIN_FULL, sjinfo,
restrictlist);
add_paths_to_joinrel(root, joinrel, rel2, rel1,
JOIN_FULL, sjinfo,
restrictlist);
/*
* If there are join quals that aren't mergeable or hashable, we
* may not be able to build any valid plan. Complain here so that
* we can give a somewhat-useful error message. (Since we have no
* flexibility of planning for a full join, there's no chance of
* succeeding later with another pair of input rels.)
*/
if (joinrel->pathlist == NIL)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("FULL JOIN is only supported with merge-joinable or hash-joinable join conditions")));
break;
case JOIN_SEMI:
/*
* We might have a normal semijoin, or a case where we don't have
* enough rels to do the semijoin but can unique-ify the RHS and
* then do an innerjoin (see comments in join_is_legal). In the
* latter case we can't apply JOIN_SEMI joining.
*/
if (bms_is_subset(sjinfo->min_lefthand, rel1->relids) &&
bms_is_subset(sjinfo->min_righthand, rel2->relids))
{
if (is_dummy_rel(rel1) || is_dummy_rel(rel2) ||
restriction_is_constant_false(restrictlist, false))
{
mark_dummy_rel(joinrel);
break;
}
add_paths_to_joinrel(root, joinrel, rel1, rel2,
JOIN_SEMI, sjinfo,
restrictlist);
}
/*
* If we know how to unique-ify the RHS and one input rel is
* exactly the RHS (not a superset) we can consider unique-ifying
* it and then doing a regular join. (The create_unique_path
* check here is probably redundant with what join_is_legal did,
* but if so the check is cheap because it's cached. So test
* anyway to be sure.)
*/
if (bms_equal(sjinfo->syn_righthand, rel2->relids) &&
create_unique_path(root, rel2, rel2->cheapest_total_path,
sjinfo) != NULL)
{
if (is_dummy_rel(rel1) || is_dummy_rel(rel2) ||
restriction_is_constant_false(restrictlist, false))
{
mark_dummy_rel(joinrel);
break;
}
add_paths_to_joinrel(root, joinrel, rel1, rel2,
JOIN_UNIQUE_INNER, sjinfo,
restrictlist);
add_paths_to_joinrel(root, joinrel, rel2, rel1,
JOIN_UNIQUE_OUTER, sjinfo,
restrictlist);
}
break;
case JOIN_ANTI:
if (is_dummy_rel(rel1) ||
restriction_is_constant_false(restrictlist, true))
{
mark_dummy_rel(joinrel);
break;
}
if (restriction_is_constant_false(restrictlist, false) &&
bms_is_subset(rel2->relids, sjinfo->syn_righthand))
mark_dummy_rel(rel2);
add_paths_to_joinrel(root, joinrel, rel1, rel2,
JOIN_ANTI, sjinfo,
restrictlist);
break;
default:
/* other values not expected here */
elog(ERROR, "unrecognized join type: %d", (int) sjinfo->jointype);
break;
}
bms_free(joinrelids);
return joinrel;
}
