On 01/30/2015 05:34 PM, Jim Nasby wrote: > On 1/30/15 2:26 PM, Josh Berkus wrote: >> This would probably work because there aren't a lot of data structures >> where people would have the same key:value pair in different locations >> in the JSON, and care about it stats-wise. Alternatetly, if the same >> key-value pair appears multiple times in the same sample row, we could >> cut the MC% by that multiple. > > Even if there were multiple occurrences, this would probably still be an > improvement. > > Another idea... at one time in the past when discussing statistics on > multiple columns, one idea was to build statistics on indexes. If we > built that, we could also do the same thing for at least JSONB (not sure > about JSON). Obviously doesn't help for stuff you haven't indexed, but > presumably if you care about performance and have any significant size > of data you've also indexed parts of the JSON, yes? I'm not clear on what you're suggesting here. I'm discussing how the stats for a JSONB field would be stored and accessed; I don't understand what that has to do with indexing. -- Josh Berkus PostgreSQL Experts Inc. http://pgexperts.com -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
