/*-------------------------------------------------------------------------
*
* 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) 1996-2013, PostgreSQL Global Development Group
+ * Portions Copyright (c) 2013-2017, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
+ * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*-------------------------------------------------------------------------
*/
+static void populate_joinrel_with_paths(PlannerInfo *root, RelOptInfo *rel1,
+ RelOptInfo *rel2, RelOptInfo *joinrel,
+ SpecialJoinInfo *sjinfo,
+ List *restrictlist);
+/*
+ * adjust_rows: tweak estimated row numbers according to the hint.
+*/
+static double
+adjust_rows(double rows, RowsHint *hint)
+{
+ double result = 0.0; /* keep compiler quiet */
+
+ if (hint->value_type == RVT_ABSOLUTE)
+ result = hint->rows;
+ else if (hint->value_type == RVT_ADD)
+ result = rows + hint->rows;
+ else if (hint->value_type == RVT_SUB)
+ result = rows - hint->rows;
+ else if (hint->value_type == RVT_MULTI)
+ result = rows * hint->rows;
+ else
+ Assert(false); /* unrecognized rows value type */
+
+ hint->base.state = HINT_STATE_USED;
+ if (result < 1.0)
+ ereport(WARNING,
+ (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
/*
* 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);
+ /* !!! 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_state->num_hints[HINT_TYPE_ROWS]; i++)
+ {
+ rows_hint = current_hint_state->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.
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
elog(ERROR, "unrecognized join type: %d", (int) sjinfo->jointype);
break;
}
-
- bms_free(joinrelids);
-
- return joinrel;
}
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