On Wed, Apr 19, 2017 at 2:39 PM, Michael Malis <michaelmal...@gmail.com> wrote:
> > TBH, I see no convincing explanation in that article of why 1300 partial > > indexes are a good idea. > > I don't like it much either. I've been trying to eliminate most of the > need for the partial indexes, but this is the current state of things. > > > *At best*, you're doing substantial work in the > > planner to avoid the first tree descent step or two in a single > > non-partial index. > > While the specific example I gave in the post could be replaced with a > non-partial index, most of the partial indexes contain predicates that > are not straightforward to index with non-partial indexes. About 85% > of the partial indexes contain a regular expression in them for CSS > selector matching. I've tried using a trigram GIN index, but it wound > up not working too well due to the data being highly redundant (almost > every CSS hierarchy contains 'div' in it). pg_trgm 1.2 or higher has code to help with very common trigrams. But to try it, you would need to upgrade PostgreSQL to 9.6. Cheers, Jeff
