Re: BUG #19760: CLUSTER loses a row the transaction inserted and then updated in a rolled-back subtransaction

Hi,

Here is a patch. rewrite_heap_dead_tuple() drops the held tuple when its
successor is dead, but that is only right if the successor's inserter
committed. If it aborted, the update never happened, so 0001 keeps the
tuple and adds its logical rewrite mapping.

Setting the hint in HeapTupleSatisfiesVacuum() is not enough. VACUUM
FULL on a catalog can see a transaction that is still open, and this
loses the pg_class row of a committed table:

s1: BEGIN; CREATE TABLE t (a int);
s1: SAVEPOINT sp; ALTER TABLE t ADD COLUMN b int; ROLLBACK TO sp;
s2: VACUUM FULL pg_class;
s1: COMMIT;

0002 is an isolation test for that case, it is optional. But I want it in
tree to prevent
future regression in that area.

Thanks,
Shihao