Raise error when affecting tuple moved into different partition.

When an update moves a row between partitions (supported since
2f178441044b), our normal logic for following update chains in READ
COMMITTED mode doesn't work anymore. Cross partition updates are
modeled as an delete from the old and insert into the new
partition. No ctid chain exists across partitions, and there's no
convenient space to introduce that link.

Not throwing an error in a partitioned context when one would have
been thrown without partitioning is obviously problematic. This commit
introduces infrastructure to detect when a tuple has been moved, not
just plainly deleted. That allows to throw an error when encountering
a deletion that's actually a move, while attempting to following a
ctid chain.

The row deleted as part of a cross partition update is marked by
pointing it's t_ctid to an invalid block, instead of self as a normal
update would.  That was deemed to be the least invasive and most
future proof way to represent the knowledge, given how few infomask
bits are there to be recycled (there's also some locking issues with
using infomask bits).

External code following ctid chains should be updated to check for
moved tuples. The most likely consequence of not doing so is a missed
error.

Author: Amul Sul, editorialized by me
Reviewed-By: Amit Kapila, Pavan Deolasee, Andres Freund, Robert Haas
Discussion: http://postgr.es/m/CAAJ_b95PkwojoYfz0bzXU8OokcTVGzN6vYGCNVUukeUDrnF3dw@mail.gmail.com

1 files changed, 139 insertions, 0 deletions

diff --git a/src/test/isolation/expected/partition-key-update-3.out b/src/test/isolation/expected/partition-key-update-3.out
new file mode 100644
index 00000000000..42dfe64ad31
--- /dev/null
+++ b/src/test/isolation/expected/partition-key-update-3.out
@@ -0,0 +1,139 @@
+Parsed test spec with 3 sessions
+
+starting permutation: s2beginrr s3beginrr s1u s2donothing s1c s2c s3donothing s3c s2select
+step s2beginrr: BEGIN ISOLATION LEVEL REPEATABLE READ;
+step s3beginrr: BEGIN ISOLATION LEVEL REPEATABLE READ;
+step s1u: UPDATE foo SET a=2, b=b || ' -> moved by session-1' WHERE a=1;
+step s2donothing: INSERT INTO foo VALUES(1, 'session-2 donothing') ON CONFLICT DO NOTHING; <waiting ...>
+step s1c: COMMIT;
+step s2donothing: <... completed>
+step s2c: COMMIT;
+step s3donothing: INSERT INTO foo VALUES(2, 'session-3 donothing'), (2, 'session-3 donothing2') ON CONFLICT DO NOTHING;
+step s3c: COMMIT;
+step s2select: SELECT * FROM foo ORDER BY a;
+a              b              
+
+1              session-2 donothing
+2              initial tuple -> moved by session-1
+
+starting permutation: s2beginrr s3beginrr s1u s3donothing s1c s3c s2donothing s2c s2select
+step s2beginrr: BEGIN ISOLATION LEVEL REPEATABLE READ;
+step s3beginrr: BEGIN ISOLATION LEVEL REPEATABLE READ;
+step s1u: UPDATE foo SET a=2, b=b || ' -> moved by session-1' WHERE a=1;
+step s3donothing: INSERT INTO foo VALUES(2, 'session-3 donothing'), (2, 'session-3 donothing2') ON CONFLICT DO NOTHING; <waiting ...>
+step s1c: COMMIT;
+step s3donothing: <... completed>
+error in steps s1c s3donothing: ERROR:  could not serialize access due to concurrent update
+step s3c: COMMIT;
+step s2donothing: INSERT INTO foo VALUES(1, 'session-2 donothing') ON CONFLICT DO NOTHING;
+step s2c: COMMIT;
+step s2select: SELECT * FROM foo ORDER BY a;
+a              b              
+
+1              session-2 donothing
+2              initial tuple -> moved by session-1
+
+starting permutation: s2beginrr s3beginrr s1u s2donothing s3donothing s1c s2c s3c s2select
+step s2beginrr: BEGIN ISOLATION LEVEL REPEATABLE READ;
+step s3beginrr: BEGIN ISOLATION LEVEL REPEATABLE READ;
+step s1u: UPDATE foo SET a=2, b=b || ' -> moved by session-1' WHERE a=1;
+step s2donothing: INSERT INTO foo VALUES(1, 'session-2 donothing') ON CONFLICT DO NOTHING; <waiting ...>
+step s3donothing: INSERT INTO foo VALUES(2, 'session-3 donothing'), (2, 'session-3 donothing2') ON CONFLICT DO NOTHING; <waiting ...>
+step s1c: COMMIT;
+step s2donothing: <... completed>
+step s3donothing: <... completed>
+error in steps s1c s2donothing s3donothing: ERROR:  could not serialize access due to concurrent update
+step s2c: COMMIT;
+step s3c: COMMIT;
+step s2select: SELECT * FROM foo ORDER BY a;
+a              b              
+
+1              session-2 donothing
+2              initial tuple -> moved by session-1
+
+starting permutation: s2beginrr s3beginrr s1u s3donothing s2donothing s1c s3c s2c s2select
+step s2beginrr: BEGIN ISOLATION LEVEL REPEATABLE READ;
+step s3beginrr: BEGIN ISOLATION LEVEL REPEATABLE READ;
+step s1u: UPDATE foo SET a=2, b=b || ' -> moved by session-1' WHERE a=1;
+step s3donothing: INSERT INTO foo VALUES(2, 'session-3 donothing'), (2, 'session-3 donothing2') ON CONFLICT DO NOTHING; <waiting ...>
+step s2donothing: INSERT INTO foo VALUES(1, 'session-2 donothing') ON CONFLICT DO NOTHING; <waiting ...>
+step s1c: COMMIT;
+step s3donothing: <... completed>
+step s2donothing: <... completed>
+error in steps s1c s3donothing s2donothing: ERROR:  could not serialize access due to concurrent update
+step s3c: COMMIT;
+step s2c: COMMIT;
+step s2select: SELECT * FROM foo ORDER BY a;
+a              b              
+
+1              session-2 donothing
+2              initial tuple -> moved by session-1
+
+starting permutation: s2begins s3begins s1u s2donothing s1c s2c s3donothing s3c s2select
+step s2begins: BEGIN ISOLATION LEVEL SERIALIZABLE;
+step s3begins: BEGIN ISOLATION LEVEL SERIALIZABLE;
+step s1u: UPDATE foo SET a=2, b=b || ' -> moved by session-1' WHERE a=1;
+step s2donothing: INSERT INTO foo VALUES(1, 'session-2 donothing') ON CONFLICT DO NOTHING; <waiting ...>
+step s1c: COMMIT;
+step s2donothing: <... completed>
+step s2c: COMMIT;
+step s3donothing: INSERT INTO foo VALUES(2, 'session-3 donothing'), (2, 'session-3 donothing2') ON CONFLICT DO NOTHING;
+step s3c: COMMIT;
+step s2select: SELECT * FROM foo ORDER BY a;
+a              b              
+
+1              session-2 donothing
+2              initial tuple -> moved by session-1
+
+starting permutation: s2begins s3begins s1u s3donothing s1c s3c s2donothing s2c s2select
+step s2begins: BEGIN ISOLATION LEVEL SERIALIZABLE;
+step s3begins: BEGIN ISOLATION LEVEL SERIALIZABLE;
+step s1u: UPDATE foo SET a=2, b=b || ' -> moved by session-1' WHERE a=1;
+step s3donothing: INSERT INTO foo VALUES(2, 'session-3 donothing'), (2, 'session-3 donothing2') ON CONFLICT DO NOTHING; <waiting ...>
+step s1c: COMMIT;
+step s3donothing: <... completed>
+error in steps s1c s3donothing: ERROR:  could not serialize access due to concurrent update
+step s3c: COMMIT;
+step s2donothing: INSERT INTO foo VALUES(1, 'session-2 donothing') ON CONFLICT DO NOTHING;
+step s2c: COMMIT;
+step s2select: SELECT * FROM foo ORDER BY a;
+a              b              
+
+1              session-2 donothing
+2              initial tuple -> moved by session-1
+
+starting permutation: s2begins s3begins s1u s2donothing s3donothing s1c s2c s3c s2select
+step s2begins: BEGIN ISOLATION LEVEL SERIALIZABLE;
+step s3begins: BEGIN ISOLATION LEVEL SERIALIZABLE;
+step s1u: UPDATE foo SET a=2, b=b || ' -> moved by session-1' WHERE a=1;
+step s2donothing: INSERT INTO foo VALUES(1, 'session-2 donothing') ON CONFLICT DO NOTHING; <waiting ...>
+step s3donothing: INSERT INTO foo VALUES(2, 'session-3 donothing'), (2, 'session-3 donothing2') ON CONFLICT DO NOTHING; <waiting ...>
+step s1c: COMMIT;
+step s2donothing: <... completed>
+step s3donothing: <... completed>
+error in steps s1c s2donothing s3donothing: ERROR:  could not serialize access due to concurrent update
+step s2c: COMMIT;
+step s3c: COMMIT;
+step s2select: SELECT * FROM foo ORDER BY a;
+a              b              
+
+1              session-2 donothing
+2              initial tuple -> moved by session-1
+
+starting permutation: s2begins s3begins s1u s3donothing s2donothing s1c s3c s2c s2select
+step s2begins: BEGIN ISOLATION LEVEL SERIALIZABLE;
+step s3begins: BEGIN ISOLATION LEVEL SERIALIZABLE;
+step s1u: UPDATE foo SET a=2, b=b || ' -> moved by session-1' WHERE a=1;
+step s3donothing: INSERT INTO foo VALUES(2, 'session-3 donothing'), (2, 'session-3 donothing2') ON CONFLICT DO NOTHING; <waiting ...>
+step s2donothing: INSERT INTO foo VALUES(1, 'session-2 donothing') ON CONFLICT DO NOTHING; <waiting ...>
+step s1c: COMMIT;
+step s3donothing: <... completed>
+step s2donothing: <... completed>
+error in steps s1c s3donothing s2donothing: ERROR:  could not serialize access due to concurrent update
+step s3c: COMMIT;
+step s2c: COMMIT;
+step s2select: SELECT * FROM foo ORDER BY a;
+a              b              
+
+1              session-2 donothing
+2              initial tuple -> moved by session-1