Improve error reporting for tuple-routing failures.

Currently, the whole row is shown without column names.  Instead,
adopt a style similar to _bt_check_unique() in ExecFindPartition()
and show the failing key: (key1, ...) = (val1, ...).

Amit Langote, per a complaint from Simon Riggs.  Reviewed by me;
I also adjusted the grammar in one of the comments.

Discussion: http://postgr.es/m/9f9dc7ae-14f0-4a25-5485-964d9bfc19bd@lab.ntt.co.jp

2 files changed, 64 insertions, 4 deletions

diff --git a/src/test/regress/expected/insert.out b/src/test/regress/expected/insert.out
index 81af3ef497..397238332b 100644
--- a/src/test/regress/expected/insert.out
+++ b/src/test/regress/expected/insert.out
@@ -234,14 +234,14 @@ insert into part_ee_ff2 values ('ff', 11);
 -- fail
 insert into range_parted values ('a', 0);
 ERROR:  no partition of relation "range_parted" found for row
-DETAIL:  Failing row contains (a, 0).
+DETAIL:  Partition key of the failing row contains (a, (b + 0)) = (a, 0).
 -- ok
 insert into range_parted values ('a', 1);
 insert into range_parted values ('a', 10);
 -- fail
 insert into range_parted values ('a', 20);
 ERROR:  no partition of relation "range_parted" found for row
-DETAIL:  Failing row contains (a, 20).
+DETAIL:  Partition key of the failing row contains (a, (b + 0)) = (a, 20).
 -- ok
 insert into range_parted values ('b', 1);
 insert into range_parted values ('b', 10);
@@ -265,10 +265,10 @@ insert into list_parted (a) values ('aA');
 -- fail (partition of part_ee_ff not found in both cases)
 insert into list_parted values ('EE', 0);
 ERROR:  no partition of relation "part_ee_ff" found for row
-DETAIL:  Failing row contains (EE, 0).
+DETAIL:  Partition key of the failing row contains (b) = (0).
 insert into part_ee_ff values ('EE', 0);
 ERROR:  no partition of relation "part_ee_ff" found for row
-DETAIL:  Failing row contains (EE, 0).
+DETAIL:  Partition key of the failing row contains (b) = (0).
 -- ok
 insert into list_parted values ('EE', 1);
 insert into part_ee_ff values ('EE', 10);
@@ -351,6 +351,10 @@ select tableoid::regclass, * from p;
  p11      | 1 | 2
 (1 row)
 
+-- check that proper message is shown after failure to route through p1
+insert into p (a, b) values (1, 5);
+ERROR:  no partition of relation "p1" found for row
+DETAIL:  Partition key of the failing row contains ((b + 0)) = (5).
 truncate p;
 alter table p add constraint check_b check (b = 3);
 -- check that correct input row is shown when constraint check_b fails on p11
@@ -386,5 +390,31 @@ with ins (a, b, c) as
  p4  | 1 |  30 |  39
 (5 rows)
 
+-- check that message shown after failure to find a partition shows the
+-- appropriate key description (or none) in various situations
+create table key_desc (a int, b int) partition by list ((a+0));
+create table key_desc_1 partition of key_desc for values in (1) partition by range (b);
+create user someone_else;
+grant select (a) on key_desc_1 to someone_else;
+grant insert on key_desc to someone_else;
+set role someone_else;
+-- no key description is shown
+insert into key_desc values (1, 1);
+ERROR:  no partition of relation "key_desc_1" found for row
+reset role;
+grant select (b) on key_desc_1 to someone_else;
+set role someone_else;
+-- key description (b)=(1) is now shown
+insert into key_desc values (1, 1);
+ERROR:  no partition of relation "key_desc_1" found for row
+DETAIL:  Partition key of the failing row contains (b) = (1).
+-- key description is not shown if key contains expression
+insert into key_desc values (2, 1);
+ERROR:  no partition of relation "key_desc" found for row
+reset role;
+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;
 -- cleanup
 drop table p, p1, p11, p12, p2, p3, p4;
diff --git a/src/test/regress/sql/insert.sql b/src/test/regress/sql/insert.sql
index 454e1ce2e7..4f19df5c25 100644
--- a/src/test/regress/sql/insert.sql
+++ b/src/test/regress/sql/insert.sql
@@ -215,6 +215,9 @@ alter table p attach partition p1 for values from (1, 2) to (1, 10);
 insert into p values (1, 2);
 select tableoid::regclass, * from p;
 
+-- check that proper message is shown after failure to route through p1
+insert into p (a, b) values (1, 5);
+
 truncate p;
 alter table p add constraint check_b check (b = 3);
 -- check that correct input row is shown when constraint check_b fails on p11
@@ -240,5 +243,32 @@ with ins (a, b, c) as
   (insert into p (b, a) select s.a, 1 from generate_series(2, 39) s(a) returning tableoid::regclass, *)
   select a, b, min(c), max(c) from ins group by a, b order by 1;
 
+-- check that message shown after failure to find a partition shows the
+-- appropriate key description (or none) in various situations
+create table key_desc (a int, b int) partition by list ((a+0));
+create table key_desc_1 partition of key_desc for values in (1) partition by range (b);
+
+create user someone_else;
+grant select (a) on key_desc_1 to someone_else;
+grant insert on key_desc to someone_else;
+
+set role someone_else;
+-- no key description is shown
+insert into key_desc values (1, 1);
+
+reset role;
+grant select (b) on key_desc_1 to someone_else;
+set role someone_else;
+-- key description (b)=(1) is now shown
+insert into key_desc values (1, 1);
+
+-- key description is not shown if key contains expression
+insert into key_desc values (2, 1);
+reset role;
+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;
+
 -- cleanup
 drop table p, p1, p11, p12, p2, p3, p4;