subject:"\[GENERAL\] Concurrency and UPDATE \[...\] FROM"

Re: [GENERAL] Concurrency and UPDATE [...] FROM

2017-07-10 Thread Thomas Munro

On Tue, Jul 11, 2017 at 6:23 AM, Seamus Abshere wrote: > The purpose is to concat new data onto existing values of c: > > UPDATE tbl > SET c = c || new_data.c > FROM ( [...] ) AS new_data > WHERE > tbl.id = new_data.id > > It appears to have a race condition: > > t0: Query A

[GENERAL] Concurrency and UPDATE [...] FROM

2017-07-10 Thread Seamus Abshere

The purpose is to concat new data onto existing values of c: UPDATE tbl SET c = c || new_data.c FROM ( [...] ) AS new_data WHERE tbl.id = new_data.id It appears to have a race condition: t0: Query A starts subquery t1: Query A starts self-join t2. Query A starts UPDATE with data from