On 16 October 2014 06:05, Amit Kapila <amit.kapil...@gmail.com> wrote: > On Thu, Oct 16, 2014 at 8:08 AM, Simon Riggs <si...@2ndquadrant.com> wrote: >> >> >> I've been trying to review this thread with the thought "what does >> this give me?". I am keen to encourage contributions and also keen to >> extend our feature set, but I do not wish to complicate our code base. >> Dilip's developments do seem to be good quality; what I question is >> whether we want this feature. >> >> This patch seems to allow me to run multiple VACUUMs at once. But I >> can already do this, with autovacuum. >> >> Is there anything this patch can do that cannot be already done with >> autovacuum? > > The difference lies in the fact that vacuumdb (or VACUUM) gives > the option to user to control the vacuum activity for cases when > autovacuum doesn't suffice the need, one of the example is to perform > vacuum via vacuumdb after pg_upgrade or some other maintenance > activity (as mentioned by Jeff upthread). So I think in all such cases > having parallel option can give benefit in terms of performance which > is already shown by Dilip upthread by running some tests (with and > without patch).
Why do we need 2 ways to do the same thing? Why not ask autovacuum to do this for you? Just send a message to autovacuum to request an immediate action. Let it manage the children and the tasks. SELECT pg_autovacuum_immediate(nworkers = N, list_of_tables); Request would allocate an additional N workers and immediately begin vacuuming the stated tables. vacuumdb can still issue the request, but the guts of this are done by the server, not a heavily modified client. If we are going to heavily modify a client then it needs to be able to run more than just one thing. Parallel psql would be nice. pg_batch? -- Simon Riggs http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
