On Mon, Feb 6, 2017 at 1:44 AM, Tom Lane <t...@sss.pgh.pa.us> wrote: > > > > 2. In the second patch, we tried to recompute attribute lists if a > relcache > > flush happens in between and index list is invalidated. We've seen > problems > > with that, especially it getting into an infinite loop with > > CACHE_CLOBBER_ALWAYS. Not clear why it happens, but apparently relcache > > flushes keep happening. > > Well, yeah: the point of CLOBBER_CACHE_ALWAYS is to make a relcache flush > happen whenever it possibly could.
Ah, ok. That explains why the retry logic as originally proposed was causing infinite loop. > The way to deal with that without > looping is to test whether the index set *actually* changed, not whether > it just might have changed. > I like this approach. I'll run the patch on a build with CACHE_CLOBBER_ALWAYS, but I'm pretty sure it will be ok. I also like the fact that retry logic is now limited to only when index set changes, which fits in the situation we're dealing with. Thanks, Pavan -- Pavan Deolasee http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services
