Robert Haas <robertmh...@gmail.com> writes: > On Thu, Sep 15, 2016 at 9:59 AM, Tom Lane <t...@sss.pgh.pa.us> wrote: >> Possibly we ought to change things so that the default value of >> min_parallel_relation_size is a fixed number of bytes rather >> than a fixed number of blocks. Not sure though.
> The reason why this was originally reckoned in blocks is because the > data is divided between the workers on the basis of a block number. > In the degenerate case where blocks < workers, the extra workers will > get no blocks at all, and thus no rows at all. Well, sure, but at any reasonable value of min_parallel_relation_size that won't be a factor. The question here is whether we want the default value to be platform-independent. I notice that both config.sgml and postgresql.conf.sample claim that the default value is 8MB, which this discussion reveals to be a lie. If you want to keep the default expressed as "1024" and not "(8 * 1024 * 1024) / BLCKSZ", we need to change the documentation. regards, tom lane -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers