Fix multi-column range partitioning constraints.

The old logic was just plain wrong.

Report by Olaf Gawenda.  Patch by Amit Langote, reviewed by
Beena Emerson and by me.  Minor adjustments by me also.

src/include/nodes/pg_list.h

@@ -182,6 +182,20 @@ list_length(const List *l)
 		 (cell1) != NULL && (cell2) != NULL;						\
 		 (cell1) = lnext(cell1), (cell2) = lnext(cell2))
 
+/*
+ * for_both_cell -
+ *	  a convenience macro which loops through two lists starting from the
+ *	  specified cells of each. This macro loops through both lists at the same
+ *	  time, stopping when either list runs out of elements.  Depending on the
+ *	  requirements of the call site, it may also be wise to assert that the
+ *	  lengths of the two lists are equal, and initcell1 and initcell2 are at
+ *	  the same position in the respective lists.
+ */
+#define for_both_cell(cell1, initcell1, cell2, initcell2)	\
+	for ((cell1) = (initcell1), (cell2) = (initcell2);		\
+		 (cell1) != NULL && (cell2) != NULL;				\
+		 (cell1) = lnext(cell1), (cell2) = lnext(cell2))
+
 /*
  * forthree -
  *	  the same for three lists

src/test/regress/expected/inherit.out

@@ -1828,3 +1828,93 @@ explain (costs off) select * from range_list_parted where a >= 30;
 
 drop table list_parted;
 drop table range_list_parted;
+-- check that constraint exclusion is able to cope with the partition
+-- constraint emitted for multi-column range partitioned tables
+create table mcrparted (a int, b int, c int) partition by range (a, abs(b), c);
+create table mcrparted0 partition of mcrparted for values from (unbounded, unbounded, unbounded) to (1, 1, 1);
+create table mcrparted1 partition of mcrparted for values from (1, 1, 1) to (10, 5, 10);
+create table mcrparted2 partition of mcrparted for values from (10, 5, 10) to (10, 10, 10);
+create table mcrparted3 partition of mcrparted for values from (11, 1, 1) to (20, 10, 10);
+create table mcrparted4 partition of mcrparted for values from (20, 10, 10) to (20, 20, 20);
+create table mcrparted5 partition of mcrparted for values from (20, 20, 20) to (unbounded, unbounded, unbounded);
+explain (costs off) select * from mcrparted where a = 0;	-- scans mcrparted0
+          QUERY PLAN          
+------------------------------
+ Append
+   ->  Seq Scan on mcrparted0
+         Filter: (a = 0)
+(3 rows)
+
+explain (costs off) select * from mcrparted where a = 10 and abs(b) < 5;	-- scans mcrparted1
+                 QUERY PLAN                  
+---------------------------------------------
+ Append
+   ->  Seq Scan on mcrparted1
+         Filter: ((a = 10) AND (abs(b) < 5))
+(3 rows)
+
+explain (costs off) select * from mcrparted where a = 10 and abs(b) = 5;	-- scans mcrparted1, mcrparted2
+                 QUERY PLAN                  
+---------------------------------------------
+ Append
+   ->  Seq Scan on mcrparted1
+         Filter: ((a = 10) AND (abs(b) = 5))
+   ->  Seq Scan on mcrparted2
+         Filter: ((a = 10) AND (abs(b) = 5))
+(5 rows)
+
+explain (costs off) select * from mcrparted where abs(b) = 5;	-- scans all partitions
+          QUERY PLAN          
+------------------------------
+ Append
+   ->  Seq Scan on mcrparted0
+         Filter: (abs(b) = 5)
+   ->  Seq Scan on mcrparted1
+         Filter: (abs(b) = 5)
+   ->  Seq Scan on mcrparted2
+         Filter: (abs(b) = 5)
+   ->  Seq Scan on mcrparted3
+         Filter: (abs(b) = 5)
+   ->  Seq Scan on mcrparted5
+         Filter: (abs(b) = 5)
+(11 rows)
+
+explain (costs off) select * from mcrparted where a > -1;	-- scans all partitions
+             QUERY PLAN              
+-------------------------------------
+ Append
+   ->  Seq Scan on mcrparted0
+         Filter: (a > '-1'::integer)
+   ->  Seq Scan on mcrparted1
+         Filter: (a > '-1'::integer)
+   ->  Seq Scan on mcrparted2
+         Filter: (a > '-1'::integer)
+   ->  Seq Scan on mcrparted3
+         Filter: (a > '-1'::integer)
+   ->  Seq Scan on mcrparted4
+         Filter: (a > '-1'::integer)
+   ->  Seq Scan on mcrparted5
+         Filter: (a > '-1'::integer)
+(13 rows)
+
+explain (costs off) select * from mcrparted where a = 20 and abs(b) = 10 and c > 10;	-- scans mcrparted4
+                        QUERY PLAN                         
+-----------------------------------------------------------
+ Append
+   ->  Seq Scan on mcrparted4
+         Filter: ((c > 10) AND (a = 20) AND (abs(b) = 10))
+(3 rows)
+
+explain (costs off) select * from mcrparted where a = 20 and c > 20; -- scans mcrparted3, mcrparte4, mcrparte5
+               QUERY PLAN                
+-----------------------------------------
+ Append
+   ->  Seq Scan on mcrparted3
+         Filter: ((c > 20) AND (a = 20))
+   ->  Seq Scan on mcrparted4
+         Filter: ((c > 20) AND (a = 20))
+   ->  Seq Scan on mcrparted5
+         Filter: ((c > 20) AND (a = 20))
+(7 rows)
+
+drop table mcrparted;

src/test/regress/expected/insert.out

@@ -435,3 +435,62 @@ revoke all on key_desc from someone_else;
 revoke all on key_desc_1 from someone_else;
 drop role someone_else;
 drop table key_desc, key_desc_1;
+-- check multi-column range partitioning expression enforces the same
+-- constraint as what tuple-routing would determine it to be
+create table mcrparted (a int, b int, c int) partition by range (a, abs(b), c);
+create table mcrparted0 partition of mcrparted for values from (unbounded, unbounded, unbounded) to (1, unbounded, unbounded);
+create table mcrparted1 partition of mcrparted for values from (2, 1, unbounded) to (10, 5, 10);
+create table mcrparted2 partition of mcrparted for values from (10, 6, unbounded) to (10, unbounded, unbounded);
+create table mcrparted3 partition of mcrparted for values from (11, 1, 1) to (20, 10, 10);
+create table mcrparted4 partition of mcrparted for values from (21, unbounded, unbounded) to (30, 20, unbounded);
+create table mcrparted5 partition of mcrparted for values from (30, 21, 20) to (unbounded, unbounded, unbounded);
+-- routed to mcrparted0
+insert into mcrparted values (0, 1, 1);
+insert into mcrparted0 values (0, 1, 1);
+-- routed to mcparted1
+insert into mcrparted values (9, 1000, 1);
+insert into mcrparted1 values (9, 1000, 1);
+insert into mcrparted values (10, 5, -1);
+insert into mcrparted1 values (10, 5, -1);
+insert into mcrparted values (2, 1, 0);
+insert into mcrparted1 values (2, 1, 0);
+-- routed to mcparted2
+insert into mcrparted values (10, 6, 1000);
+insert into mcrparted2 values (10, 6, 1000);
+insert into mcrparted values (10, 1000, 1000);
+insert into mcrparted2 values (10, 1000, 1000);
+-- no partition exists, nor does mcrparted3 accept it
+insert into mcrparted values (11, 1, -1);
+ERROR:  no partition of relation "mcrparted" found for row
+DETAIL:  Partition key of the failing row contains (a, abs(b), c) = (11, 1, -1).
+insert into mcrparted3 values (11, 1, -1);
+ERROR:  new row for relation "mcrparted3" violates partition constraint
+DETAIL:  Failing row contains (11, 1, -1).
+-- routed to mcrparted5
+insert into mcrparted values (30, 21, 20);
+insert into mcrparted5 values (30, 21, 20);
+insert into mcrparted4 values (30, 21, 20);	-- error
+ERROR:  new row for relation "mcrparted4" violates partition constraint
+DETAIL:  Failing row contains (30, 21, 20).
+-- check rows
+select tableoid::regclass::text, * from mcrparted order by 1;
+  tableoid  | a  |  b   |  c   
+------------+----+------+------
+ mcrparted0 |  0 |    1 |    1
+ mcrparted0 |  0 |    1 |    1
+ mcrparted1 |  9 | 1000 |    1
+ mcrparted1 |  9 | 1000 |    1
+ mcrparted1 | 10 |    5 |   -1
+ mcrparted1 | 10 |    5 |   -1
+ mcrparted1 |  2 |    1 |    0
+ mcrparted1 |  2 |    1 |    0
+ mcrparted2 | 10 |    6 | 1000
+ mcrparted2 | 10 |    6 | 1000
+ mcrparted2 | 10 | 1000 | 1000
+ mcrparted2 | 10 | 1000 | 1000
+ mcrparted5 | 30 |   21 |   20
+ mcrparted5 | 30 |   21 |   20
+(14 rows)
+
+-- cleanup
+drop table mcrparted;

src/test/regress/sql/inherit.sql

@@ -643,3 +643,21 @@ explain (costs off) select * from range_list_parted where a >= 30;
 
 drop table list_parted;
 drop table range_list_parted;
+
+-- check that constraint exclusion is able to cope with the partition
+-- constraint emitted for multi-column range partitioned tables
+create table mcrparted (a int, b int, c int) partition by range (a, abs(b), c);
+create table mcrparted0 partition of mcrparted for values from (unbounded, unbounded, unbounded) to (1, 1, 1);
+create table mcrparted1 partition of mcrparted for values from (1, 1, 1) to (10, 5, 10);
+create table mcrparted2 partition of mcrparted for values from (10, 5, 10) to (10, 10, 10);
+create table mcrparted3 partition of mcrparted for values from (11, 1, 1) to (20, 10, 10);
+create table mcrparted4 partition of mcrparted for values from (20, 10, 10) to (20, 20, 20);
+create table mcrparted5 partition of mcrparted for values from (20, 20, 20) to (unbounded, unbounded, unbounded);
+explain (costs off) select * from mcrparted where a = 0;	-- scans mcrparted0
+explain (costs off) select * from mcrparted where a = 10 and abs(b) < 5;	-- scans mcrparted1
+explain (costs off) select * from mcrparted where a = 10 and abs(b) = 5;	-- scans mcrparted1, mcrparted2
+explain (costs off) select * from mcrparted where abs(b) = 5;	-- scans all partitions
+explain (costs off) select * from mcrparted where a > -1;	-- scans all partitions
+explain (costs off) select * from mcrparted where a = 20 and abs(b) = 10 and c > 10;	-- scans mcrparted4
+explain (costs off) select * from mcrparted where a = 20 and c > 20; -- scans mcrparted3, mcrparte4, mcrparte5
+drop table mcrparted;

src/test/regress/sql/insert.sql

@@ -289,3 +289,46 @@ revoke all on key_desc from someone_else;
 revoke all on key_desc_1 from someone_else;
 drop role someone_else;
 drop table key_desc, key_desc_1;
+
+-- check multi-column range partitioning expression enforces the same
+-- constraint as what tuple-routing would determine it to be
+create table mcrparted (a int, b int, c int) partition by range (a, abs(b), c);
+create table mcrparted0 partition of mcrparted for values from (unbounded, unbounded, unbounded) to (1, unbounded, unbounded);
+create table mcrparted1 partition of mcrparted for values from (2, 1, unbounded) to (10, 5, 10);
+create table mcrparted2 partition of mcrparted for values from (10, 6, unbounded) to (10, unbounded, unbounded);
+create table mcrparted3 partition of mcrparted for values from (11, 1, 1) to (20, 10, 10);
+create table mcrparted4 partition of mcrparted for values from (21, unbounded, unbounded) to (30, 20, unbounded);
+create table mcrparted5 partition of mcrparted for values from (30, 21, 20) to (unbounded, unbounded, unbounded);
+
+-- routed to mcrparted0
+insert into mcrparted values (0, 1, 1);
+insert into mcrparted0 values (0, 1, 1);
+
+-- routed to mcparted1
+insert into mcrparted values (9, 1000, 1);
+insert into mcrparted1 values (9, 1000, 1);
+insert into mcrparted values (10, 5, -1);
+insert into mcrparted1 values (10, 5, -1);
+insert into mcrparted values (2, 1, 0);
+insert into mcrparted1 values (2, 1, 0);
+
+-- routed to mcparted2
+insert into mcrparted values (10, 6, 1000);
+insert into mcrparted2 values (10, 6, 1000);
+insert into mcrparted values (10, 1000, 1000);
+insert into mcrparted2 values (10, 1000, 1000);
+
+-- no partition exists, nor does mcrparted3 accept it
+insert into mcrparted values (11, 1, -1);
+insert into mcrparted3 values (11, 1, -1);
+
+-- routed to mcrparted5
+insert into mcrparted values (30, 21, 20);
+insert into mcrparted5 values (30, 21, 20);
+insert into mcrparted4 values (30, 21, 20);	-- error
+
+-- check rows
+select tableoid::regclass::text, * from mcrparted order by 1;
+
+-- cleanup
+drop table mcrparted;