On 09/15/2014 02:16 PM, Robert Haas wrote: > On Mon, Sep 15, 2014 at 3:09 PM, Josh Berkus <j...@agliodbs.com> wrote: >> On 09/15/2014 10:23 AM, Claudio Freire wrote: >>> Now, large small keys could be 200 or 2000, or even 20k. I'd guess >>> several should be tested to find the shape of the curve. >> >> Well, we know that it's not noticeable with 200, and that it is >> noticeable with 100K. It's only worth testing further if we think that >> having more than 200 top-level keys in one JSONB value is going to be a >> use case for more than 0.1% of our users. I personally do not. > > FWIW, I have written one (1) application that uses JSONB and it has > one sub-object (not the top-level object) that in the most typical > configuration contains precisely 270 keys. Now, granted, that is not > the top-level object, if that distinction is actually relevant here, > but color me just a bit skeptical of this claim anyway. This was just > a casual thing I did for my own use, not anything industrial strength, > so it's hard to believe I'm stressing the system more than 99.9% of > users will.
Actually, having the keys all at the same level *is* relevant for the issue we're discussing. If those 270 keys are organized in a tree, it's not the same as having them all on one level (and not as problematic). -- Josh Berkus PostgreSQL Experts Inc. http://pgexperts.com -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers