On Wed, Oct 19, 2016 at 06:58:05PM +0200, Simon Riggs wrote: > >> I agree. Also, I think the recheck mechanism will have to be something like > >> what I wrote for WARM i.e. only checking for index quals won't be enough > >> and we > >> would actually need to verify that the heap tuple satisfies the key in the > >> indirect index. > > > > I personally would like to see how far we get with WARM before adding > > this feature that requires a DBA to evaluate and enable it. > > Assuming WARM is accepted, that *might* be fine.
First, I love WARM because everyone gets the benefits by default. For example, a feature that improves performance by 10% but is only used by 1% of users has a usefulness of 0.1% --- at least that is how I think of it. > What we should ask is what is the difference between indirect indexes > and WARM and to what extent they overlap. > > My current understanding is that WARM won't help you if you update > parts of a JSON document and/or use GIN indexes, but is effective > without needing to add a new index type and will be faster for > retrieval than indirect indexes. > > So everybody please chirp in with benefits or comparisons. I am not sure we have even explored all the limits of WARM with btree indexes --- I haven't heard anyone talk about non-btree indexes yet. -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + As you are, so once was I. As I am, so you will be. + + Ancient Roman grave inscription + -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers