improve update/delete on a missing key (mentioned in issue #104)

Author: funbringer

expected/pathman_basic.out

@@ -1657,7 +1657,7 @@ EXPLAIN (COSTS OFF) SELECT * FROM test.range_rel WHERE dt > '2010-12-15';
 CREATE TABLE test.tmp (id INTEGER NOT NULL, value INTEGER NOT NULL);
 INSERT INTO test.tmp VALUES (1, 1), (2, 2);
 /* Test UPDATE and DELETE */
-EXPLAIN (COSTS OFF) UPDATE test.range_rel SET value = 111 WHERE dt = '2010-06-15';
+EXPLAIN (COSTS OFF) UPDATE test.range_rel SET value = 111 WHERE dt = '2010-06-15';	/* have partitions for this 'dt' */
                                    QUERY PLAN                                   
 --------------------------------------------------------------------------------
  Update on range_rel_6
@@ -1672,7 +1672,7 @@ SELECT * FROM test.range_rel WHERE dt = '2010-06-15';
  166 | Tue Jun 15 00:00:00 2010 |   111
 (1 row)
 
-EXPLAIN (COSTS OFF) DELETE FROM test.range_rel WHERE dt = '2010-06-15';
+EXPLAIN (COSTS OFF) DELETE FROM test.range_rel WHERE dt = '2010-06-15';	/* have partitions for this 'dt' */
                                    QUERY PLAN                                   
 --------------------------------------------------------------------------------
  Delete on range_rel_6
@@ -1686,6 +1686,34 @@ SELECT * FROM test.range_rel WHERE dt = '2010-06-15';
 ----+----+-------
 (0 rows)
 
+EXPLAIN (COSTS OFF) UPDATE test.range_rel SET value = 222 WHERE dt = '1990-01-01';	/* no partitions for this 'dt' */
+                                   QUERY PLAN                                   
+--------------------------------------------------------------------------------
+ Update on range_rel
+   ->  Seq Scan on range_rel
+         Filter: (dt = 'Mon Jan 01 00:00:00 1990'::timestamp without time zone)
+(3 rows)
+
+UPDATE test.range_rel SET value = 111 WHERE dt = '1990-01-01';
+SELECT * FROM test.range_rel WHERE dt = '1990-01-01';
+ id | dt | value 
+----+----+-------
+(0 rows)
+
+EXPLAIN (COSTS OFF) DELETE FROM test.range_rel WHERE dt < '1990-01-01';	/* no partitions for this 'dt' */
+                                   QUERY PLAN                                   
+--------------------------------------------------------------------------------
+ Delete on range_rel
+   ->  Seq Scan on range_rel
+         Filter: (dt < 'Mon Jan 01 00:00:00 1990'::timestamp without time zone)
+(3 rows)
+
+DELETE FROM test.range_rel WHERE dt < '1990-01-01';
+SELECT * FROM test.range_rel WHERE dt < '1990-01-01';
+ id | dt | value 
+----+----+-------
+(0 rows)
+
 EXPLAIN (COSTS OFF) UPDATE test.range_rel r SET value = t.value FROM test.tmp t WHERE r.dt = '2010-01-01' AND r.id = t.id;
                                          QUERY PLAN                                         
 --------------------------------------------------------------------------------------------

sql/pathman_basic.sql

@@ -503,18 +503,31 @@ EXPLAIN (COSTS OFF) SELECT * FROM test.range_rel WHERE dt > '2010-12-15';
 CREATE TABLE test.tmp (id INTEGER NOT NULL, value INTEGER NOT NULL);
 INSERT INTO test.tmp VALUES (1, 1), (2, 2);
 
+
 /* Test UPDATE and DELETE */
-EXPLAIN (COSTS OFF) UPDATE test.range_rel SET value = 111 WHERE dt = '2010-06-15';
+EXPLAIN (COSTS OFF) UPDATE test.range_rel SET value = 111 WHERE dt = '2010-06-15';	/* have partitions for this 'dt' */
 UPDATE test.range_rel SET value = 111 WHERE dt = '2010-06-15';
 SELECT * FROM test.range_rel WHERE dt = '2010-06-15';
-EXPLAIN (COSTS OFF) DELETE FROM test.range_rel WHERE dt = '2010-06-15';
+
+EXPLAIN (COSTS OFF) DELETE FROM test.range_rel WHERE dt = '2010-06-15';	/* have partitions for this 'dt' */
 DELETE FROM test.range_rel WHERE dt = '2010-06-15';
 SELECT * FROM test.range_rel WHERE dt = '2010-06-15';
+
+EXPLAIN (COSTS OFF) UPDATE test.range_rel SET value = 222 WHERE dt = '1990-01-01';	/* no partitions for this 'dt' */
+UPDATE test.range_rel SET value = 111 WHERE dt = '1990-01-01';
+SELECT * FROM test.range_rel WHERE dt = '1990-01-01';
+
+EXPLAIN (COSTS OFF) DELETE FROM test.range_rel WHERE dt < '1990-01-01';	/* no partitions for this 'dt' */
+DELETE FROM test.range_rel WHERE dt < '1990-01-01';
+SELECT * FROM test.range_rel WHERE dt < '1990-01-01';
+
 EXPLAIN (COSTS OFF) UPDATE test.range_rel r SET value = t.value FROM test.tmp t WHERE r.dt = '2010-01-01' AND r.id = t.id;
 UPDATE test.range_rel r SET value = t.value FROM test.tmp t WHERE r.dt = '2010-01-01' AND r.id = t.id;
+
 EXPLAIN (COSTS OFF) DELETE FROM test.range_rel r USING test.tmp t WHERE r.dt = '2010-01-02' AND r.id = t.id;
 DELETE FROM test.range_rel r USING test.tmp t WHERE r.dt = '2010-01-02' AND r.id = t.id;
 
+
 /* Create range partitions from whole range */
 SELECT drop_partitions('test.range_rel');
 

src/planner_tree_modification.c

@@ -249,6 +249,7 @@ handle_modification_query(Query *parse, ParamListInfo params)
 	Expr				   *expr;
 	WalkerContext			context;
 	Index					result_rel;
+	int						num_selected;
 
 	/* Fetch index of result relation */
 	result_rel = parse->resultRelation;
@@ -291,12 +292,10 @@ handle_modification_query(Query *parse, ParamListInfo params)
 	wrap = walk_expr_tree(expr, &context);
 
 	ranges = irange_list_intersection(ranges, wrap->rangeset);
+	num_selected = irange_list_length(ranges);
 
-	/*
-	 * If only one partition is affected,
-	 * substitute parent table with the partition.
-	 */
-	if (irange_list_length(ranges) == 1)
+	/* Special case #1: only one partition is affected */
+	if (num_selected == 1)
 	{
 		IndexRange irange = linitial_irange(ranges);
 
@@ -361,6 +360,13 @@ handle_modification_query(Query *parse, ParamListInfo params)
 			rte->inh = false;
 		}
 	}
+
+	/* Special case #2: no partitions are affected */
+	else if (num_selected == 0)
+	{
+		/* HACK: unset the 'inh' flag (no children) */
+		rte->inh = false;
+	}
 }