On Tue, Jan 31, 2023 at 4:25 AM Tom Lane <t...@sss.pgh.pa.us> wrote: > > Peter Smith <smithpb2...@gmail.com> writes: > > I'd forgotten about the 'streaming' option -- AFAIK this was > > previously a boolean parameter and so its [= value] part can also be > > omitted. However, in PG16 streaming became an enum type > > (on/off/parallel), and the value can still be omitted but that is not > > really being covered by the new generic text note about booleans added > > by yesterday's patch. > > Hmph. I generally think that options defined like this (it's a boolean, > except it isn't) are a bad idea, and would prefer to see that API > rethought while we still can. >
We have discussed this during development and considered using a separate option like parallel = on (or say parallel_workers = n) but there were challenges with the same. See discussion in email [1]. We also checked that we have various other places using something similar for options. For example COPY commands option: HEADER [ boolean | MATCH ]. Then GUCs like synchronous_commit/constraint_exclusion/huge_pages/backslash_quote have similar values. Then some of the reloptions like buffering, vacuum_index_cleanup also have off/on/auto values. I think having an enum where off/on are present is already used. In this case, the main reason is that after discussion we felt it is better to have streaming as an enum with values off/on/parallel instead of introducing a new option. [1] - https://www.postgresql.org/message-id/CAA4eK1Kt67RdW0WTR-LTxasj3pyukPCYhfA0arDUNnsz2wh03A%40mail.gmail.com -- With Regards, Amit Kapila.
