On 1/10/17 11:23 AM, Claudio Freire wrote: > On Tue, Jan 10, 2017 at 6:42 AM, Masahiko Sawada <sawada.m...@gmail.com> > wrote: >>> Does this work negate the other work to allow VACUUM to use > >>> 1GB memory? >> >> Partly yes. Because memory space for dead TIDs needs to be allocated >> in DSM before vacuum worker launches, parallel lazy vacuum cannot use >> such a variable amount of memory as that work does. But in >> non-parallel lazy vacuum, that work would be effective. We might be >> able to do similar thing using DSA but I'm not sure that is better. > > I think it would work well with DSA as well. > > Just instead of having a single segment list, you'd have one per worker. > > Since workers work on disjoint tid sets, that shouldn't pose a problem. > > The segment list can be joined together later rather efficiently > (simple logical joining of the segment pointer arrays) for the index > scan phases.
It's been a while since there was any movement on this patch and quite a few issues have been raised. Have you tried the approaches that Claudio suggested? -- -David da...@pgmasters.net -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
