/*-------------------------------------------------------------------------
*
* make_join_rel.c
- * Routines copied from PostgreSQL core distribution.
+ * Routines copied from PostgreSQL core distribution with some
+ * modifications.
*
* src/backend/optimizer/path/joinrels.c
* make_join_rel()
*
- * Portions Copyright (c) 2013, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
- * Portions Copyright (c) 1996-2012, PostgreSQL Global Development Group
+ * Portions Copyright (c) 2013-2020, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*-------------------------------------------------------------------------
*/
/*
- * 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.
+ * adjust_rows: tweak estimated row numbers according to the hint.
*/
static double
adjust_rows(double rows, RowsHint *hint)
hint->base.state = HINT_STATE_USED;
if (result < 1.0)
ereport(WARNING,
- (errmsg("make rows estimation 1 since below 1 : %s",
+ (errmsg("Force estimate to be at least one row, to avoid possible divide-by-zero when interpolating costs : %s",
hint->base.hint_str)));
result = clamp_row_est(result);
elog(DEBUG1, "adjusted rows %d to %d", (int) rows, (int) result);
return result;
}
+/*
+ * 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)
{
RelOptInfo *joinrel;
List *restrictlist;
- RowsHint *rows_hint = NULL;
- int i;
-
/* We should never try to join two overlapping sets of rels. */
Assert(!bms_overlap(rel1->relids, rel2->relids));
/*
* 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
+ * join_info_list. Make up a SpecialJoinInfo so that selectivity
* estimation functions will know what's being joined.
*/
if (sjinfo == NULL)
/* we don't bother trying to make the remaining fields valid */
sjinfo->lhs_strict = false;
sjinfo->delay_upper_joins = false;
- sjinfo->join_quals = NIL;
+ sjinfo->semi_can_btree = false;
+ sjinfo->semi_can_hash = false;
+ sjinfo->semi_operators = NIL;
+ sjinfo->semi_rhs_exprs = NIL;
}
/*
joinrel = build_join_rel(root, joinrelids, rel1, rel2, sjinfo,
&restrictlist);
- /* Apply appropriate Rows hint to the join node, if any. */
- for (i = 0; i < current_hint->num_hints[HINT_TYPE_ROWS]; i++)
+ /* !!! START: HERE IS THE PART WHICH ADDED FOR PG_HINT_PLAN !!! */
{
- rows_hint = current_hint->rows_hints[i];
+ RowsHint *rows_hint = NULL;
+ int i;
+ RowsHint *justforme = NULL;
+ RowsHint *domultiply = NULL;
- /*
- * This Rows hint specifies aliasname is error, or does not exist in
- * query.
- */
- if (!rows_hint->joinrelids ||
- rows_hint->base.state == HINT_STATE_ERROR)
- continue;
- if (bms_equal(joinrelids, rows_hint->joinrelids))
+ /* Search for applicable rows hint for this join node */
+ for (i = 0; i < current_hint_state->num_hints[HINT_TYPE_ROWS]; i++)
{
+ rows_hint = current_hint_state->rows_hints[i];
+
/*
- * This join RelOptInfo is exactly a Rows hint specifies, so adjust
- * rows estimateion with the hint's content. Here we never have
- * another hint which has same relation combination, so we can skip
- * rest of hints.
+ * Skip this rows_hint if it is invalid from the first or it
+ * doesn't target any join rels.
*/
- if (rows_hint->base.state == HINT_STATE_NOTUSED)
- joinrel->rows = adjust_rows(joinrel->rows, rows_hint);
+ 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;
+ }
}
- else if (bms_is_subset(rows_hint->joinrelids, rel1->relids) ||
- bms_is_subset(rows_hint->joinrelids, rel2->relids))
+
+ if (justforme)
{
/*
- * Otherwise if the relation combination specified in thee Rows
- * hint is subset of the set of join elements, re-estimate rows and
- * costs again to reflect the adjustment done in down. This is
- * necessary for the first permutation of the combination the
- * relations, but it's difficult to determine that this is the
- * first, so do this everytime.
+ * 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.
*/
- set_joinrel_size_estimates(root, joinrel, rel1, rel2, sjinfo,
- restrictlist);
+ if (justforme->base.state == HINT_STATE_NOTUSED)
+ joinrel->rows = adjust_rows(joinrel->rows, justforme);
}
- else if (bms_is_subset(rows_hint->joinrelids, joinrelids))
+ else
{
- /*
- * If the combination specifed in the Rows hints is subset of the
- * join relation and spreads over both children,
- *
- * We do adjust rows estimation only when the value type was
- * multiplication, because other value types are meanless.
- */
- if (rows_hint->value_type == RVT_MULTI)
+ 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, rows_hint);
+
+ 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
return joinrel;
}
+ /* Add paths to the join relation. */
+ populate_joinrel_with_paths(root, rel1, rel2, joinrel, sjinfo,
+ restrictlist);
+
+ bms_free(joinrelids);
+
+ return joinrel;
+}
+
+/*
+ * populate_joinrel_with_paths
+ * Add paths to the given joinrel for given pair of joining relations. The
+ * SpecialJoinInfo provides details about the join and the restrictlist
+ * contains the join clauses and the other clauses applicable for given pair
+ * of the joining relations.
+ */
+static void
+populate_joinrel_with_paths(PlannerInfo *root, RelOptInfo *rel1,
+ RelOptInfo *rel2, RelOptInfo *joinrel,
+ SpecialJoinInfo *sjinfo, List *restrictlist)
+{
/*
* 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
{
case JOIN_INNER:
if (is_dummy_rel(rel1) || is_dummy_rel(rel2) ||
- restriction_is_constant_false(restrictlist, false))
+ restriction_is_constant_false(restrictlist, joinrel, false))
{
mark_dummy_rel(joinrel);
break;
break;
case JOIN_LEFT:
if (is_dummy_rel(rel1) ||
- restriction_is_constant_false(restrictlist, true))
+ restriction_is_constant_false(restrictlist, joinrel, true))
{
mark_dummy_rel(joinrel);
break;
}
- if (restriction_is_constant_false(restrictlist, false) &&
+ if (restriction_is_constant_false(restrictlist, joinrel, false) &&
bms_is_subset(rel2->relids, sjinfo->syn_righthand))
mark_dummy_rel(rel2);
add_paths_to_joinrel(root, joinrel, rel1, rel2,
break;
case JOIN_FULL:
if ((is_dummy_rel(rel1) && is_dummy_rel(rel2)) ||
- restriction_is_constant_false(restrictlist, true))
+ restriction_is_constant_false(restrictlist, joinrel, true))
{
mark_dummy_rel(joinrel);
break;
bms_is_subset(sjinfo->min_righthand, rel2->relids))
{
if (is_dummy_rel(rel1) || is_dummy_rel(rel2) ||
- restriction_is_constant_false(restrictlist, false))
+ restriction_is_constant_false(restrictlist, joinrel, false))
{
mark_dummy_rel(joinrel);
break;
sjinfo) != NULL)
{
if (is_dummy_rel(rel1) || is_dummy_rel(rel2) ||
- restriction_is_constant_false(restrictlist, false))
+ restriction_is_constant_false(restrictlist, joinrel, false))
{
mark_dummy_rel(joinrel);
break;
break;
case JOIN_ANTI:
if (is_dummy_rel(rel1) ||
- restriction_is_constant_false(restrictlist, true))
+ restriction_is_constant_false(restrictlist, joinrel, true))
{
mark_dummy_rel(joinrel);
break;
}
- if (restriction_is_constant_false(restrictlist, false) &&
+ if (restriction_is_constant_false(restrictlist, joinrel, false) &&
bms_is_subset(rel2->relids, sjinfo->syn_righthand))
mark_dummy_rel(rel2);
add_paths_to_joinrel(root, joinrel, rel1, rel2,
break;
}
- bms_free(joinrelids);
-
- return joinrel;
+ /* Apply partitionwise join technique, if possible. */
+ try_partitionwise_join(root, rel1, rel2, joinrel, sjinfo, restrictlist);
}
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