X-Git-Url: http://git.osdn.net/view?a=blobdiff_plain;f=make_join_rel.c;h=94bbfb8a84db95f0d2a49449b99695804d4b5c5b;hb=2a9e14e50905decc0d37506284fbfb5bf1e094ac;hp=c05824655b3c9ea92731260a405784d50f8ece4e;hpb=67fc7f82e64c094808a05740cb9c55c0f121c1c6;p=pghintplan%2Fpg_hint_plan.git

diff --git a/make_join_rel.c b/make_join_rel.c
index c058246..94bbfb8 100644
--- a/make_join_rel.c
+++ b/make_join_rel.c
@@ -1,18 +1,50 @@
 /*-------------------------------------------------------------------------
  *
  * 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
  *
  *-------------------------------------------------------------------------
  */
 
 /*
+ * 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
  *	   the two given rels, and add to it path information for paths
@@ -60,7 +92,7 @@ make_join_rel(PlannerInfo *root, RelOptInfo *rel1, RelOptInfo *rel2)
 
 	/*
 	 * 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)
@@ -75,7 +107,10 @@ make_join_rel(PlannerInfo *root, RelOptInfo *rel1, RelOptInfo *rel2)
 		/* 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;
 	}
 
 	/*
@@ -85,6 +120,84 @@ make_join_rel(PlannerInfo *root, RelOptInfo *rel1, RelOptInfo *rel2)
 	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.