On Wed, Oct 14, 2020 at 5:23 PM Tom Lane <t...@sss.pgh.pa.us> wrote: > Magnus Hagander <mag...@hagander.net> writes: > > On Wed, Oct 14, 2020 at 5:10 PM Tom Lane <t...@sss.pgh.pa.us> wrote: > >> It's fairly annoying that this doesn't work: > >> regression=# select pg_size_bytes(setting||' '||unit) from pg_settings > >> where name = 'shared_buffers'; > > > Actually thinking though, surely *this* particular case can be spelled > as: > > SELECT pg_size_bytes(current_setting('shared_buffers')) > > Yeah, that might be the most recommendable way. > > > Or if doing it off pg_settings: > > SELECT setting::bigint * pg_size_bytes(unit) from pg_settings where > > name='shared_buffers' > > No, because that will fail for any unit other than '8kB', eg > > regression=# select pg_size_bytes('MB'); > ERROR: invalid size: "MB" >
Right, but it would certainly work for *this* case using pg_asettings, is what I meant. That said, I think it'd then actually be better to teach pg_size_bytes to know that "MB" is the same as "1MB" and parse that. That might be something that would actually be useful in other cases as well -- basically as a way to get conversion units in general. Basically if the string is "unit only" then consider that as "1 unit". -- Magnus Hagander Me: https://www.hagander.net/ <http://www.hagander.net/> Work: https://www.redpill-linpro.com/ <http://www.redpill-linpro.com/>