On 2016/04/15 12:02, Robert Haas wrote: > As previously threatened, I have written some user documentation for > parallel query. I put it up here: > > https://wiki.postgresql.org/wiki/Parallel_Query > > This is not totally comprehensive and I can think of a few more > details that could be added, but it's a pretty good high-level > overview of what got into 9.6. After this has gotten some feedback > and polishing, I would like to add a version of this to the SGML > documentation somewhere. I am not sure where it would fit, but I > think it's good to document stuff like this.
Looking at the "Function Labeling For Parallel Safety" section. There is a sentence: "Functions must be marked PARALLEL UNSAFE if they write to the database, access sequences, change the transaction state even temporarily (e.g. a PL/pgsql function which establishes an EXCEPTION block to catch errors), or make persistent changes to settings." Then looking at the "postgres_fdw vs. force_parallel_mode on ppc" thread [1], I wonder if a note on the lines of "or a function that creates *new* connection(s) to remote server(s)" may be in order. Overkill? Thanks, Amit [1] http://www.postgresql.org/message-id/CAEepm=1_saV7WJQWqgZfeNL954=nhtvcaoyuu6fxet01rm2...@mail.gmail.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
