Hello everyone. I see strange beaviour of txid_status with one of my production servers.
SELECT txid_status(txid_current()) -> NULL SELECT txid_current() -> 4447342811 It also returns null for recent commited and aborted transactions. SELECT datname, age(datfrozenxid), datfrozenxid FROM pg_database; template 0239961994 4207340131 postgres 289957756 4157344369 <(415)%20734-4369> template1 289957661 4157344464 <(415)%20734-4464> project 682347934 3764954191 GDB shows it happens because of TransactionIdPrecedes(xid, ShmemVariableCache->oldestClogXid)) at txid.c:155. xid_epoch = 1 xid = 150227913 now_epoch = 1 now_epoch_last_xid = 150468261 ShmemVariableCache->oldestClogXid = 2207340131 <(220)%20734-0131> The strangest thing is ShmemVariableCache->oldestClogXid == 2207340131 <(220)%20734-0131> which is greater than current xid without an epoch (150227913) . Postgres was updated from 9.6 to PostgreSQL 10.4 (Ubuntu 10.4-2.pgdg14.04+1) on x86_64-pc-linux-gnu, compiled by gcc (Ubuntu 4.8.4-2ubuntu1~14.04.4) 4.8.4, 64-bit. Also, another small issue: On the same database: SELECT txid_status(BIGINT '4294967295') -> 'commited'. SELECT txid_status(BIGINT '4294967296') -> NULL Both tx ids are from my head and not valid. First 'commited' happends because int32 overflow: TransactionIdPrecedes(59856482, 2207340131 <(220)%20734-0131>) == false Could anyone help me with understanding of txid_status behaviour? Thanks, Michail.
