Thanks Adrian. This is 'vanilla' postgres as far as I know (unlike their postgres-flavoured Aurora product).
b2bc_owner@b2bcreditonline=> select version(); version --------------------------------------------------------------------------------------------------------- PostgreSQL 13.1 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-11), 64-bit
On 3/29/21 4:39 PM, Steve Baldwin wrote: > Hi all, > > I know this is going to sound weird/unbelievable, but I'm trying to come > up with an explanation for what I've observed. > > First, a couple of data points. The instance is running on AWS RDS and > is on version 13.1. All my timestamps and elapsed times were taken from > the postgres log (converted to my local tz). > > 2021-03-30 05:47:40.989+11 Session A begins a new transaction > 2021-03-30 05:47:41.006+11 Session A inserts a single row into table A > 2021-03-30 05:47:41.031+11 Session A inserts two rows into table B > 2021-03-30 05:47:41.039+11 Session A commits (duration = 3.022 ms) > > 2021-03-30 05:47:41.082+11 Session B begins a new transaction > 2021-03-30 05:47:41.083+11 Session B fetches one of the inserted rows > from table B > 2021-03-30 05:47:41.085+11 Session B attempts to fetch the inserted row > from table A using the primary key. Fetch returns zero rows. > 2021-03-30 05:47:41.087+11 Session B aborts the transaction with rollback > > 2021-03-30 05:47:42.143+11 Session C begins a new transaction > 2021-03-30 05:47:42.146+11 Session C fetches the same row as session B above > 2021-03-30 05:47:42.228+11 Session C attempts the same query on table A > as session B above. The fetch returns 1 row, and session C continues > processing. > > I can't imagine how Session B could fail to fetch the row from table A > given that the commit has completed prior to Session B starting its > transaction. > > Any suggestions?
