On 2018/07/31 5:27, Peter Eisentraut wrote: > On 19/07/2018 06:17, Amit Langote wrote: >> When playing with this, I observed that a less user-friendly error message >> is emitted if multiple sessions race to create the same collation. >> >> Session 1: >> begin; >> create collation collname (...); >> >> Session 2: >> create collation collname (...); >> <blocks for lock on pg_collation> >> >> Session 1: >> commit; >> >> Session 2: >> ERROR: duplicate key value violates unique constraint >> "pg_collation_name_enc_nsp_index" >> DETAIL: Key (collname, collencoding, collnamespace)=(collname, 6, 2200) >> already exists. > > You get the same behavior with for example CREATE FUNCTION or CREATE > TYPE. I don't think we need to fix this specifically for CREATE COLLATION.
Hmm, yeah. Although fixing the race for CREATE COLLATION seems easier than other cases due to the self-exclusive lock on the catalog, that doesn't necessarily mean we have to. Thanks, Amit
