On Fri, Sep 26, 2014 at 11:47 AM, Alvaro Herrera <alvhe...@2ndquadrant.com> wrote:
> Gavin Flower wrote: > > > Curious: would it be both feasible and useful to have multiple > > workers process a 'large' table, without complicating things too > > much? The could each start at a different position in the file. > > Feasible: no. Useful: maybe, we don't really know. (You could just as > well have a worker at double the speed, i.e. double vacuum_cost_limit). > Vacuum_cost_delay is already 0 by default. So unless you changed that, vacuum_cost_limit does not take effect under vacuumdb. It is pretty easy for vacuum to be CPU limited, and even easier for analyze to be CPU limited (It does a lot of sorting). I think analyzing is the main use case for this patch, to shorten the pg_upgrade window. At least, that is how I anticipate using it. Cheers, Jeff
