On 24 January 2017 at 11:23, Jim Nasby <jim.na...@bluetreble.com> wrote:
> I finally got all the kinks worked out and did some testing with python 3. > Performance for my test [1] improved ~460% when returning a dict of lists > (as opposed to the current list of dicts). Based on previous testing, I > expect that using this method to return a list of dicts will be about 8% > slower. The inconsistency in results on 2.7 has to do with how python 2 > handles ints. Impressive results. > I think the last step here is to figure out how to support switching between > the current behavior and the "columnar" behavior of a dict of lists. That sounds like it'd be much better approached as a separate, later patch. If I understand you correctly, you propose to return the resultset a b 1 10 2 20 which is currently returned as [ {"a":1, "b":10}, {"a":2, "b":20} ] instead as { "a": [1, 2], "b": [10, 20] } ? If so I see that as a lot more of a niche thing. I can see why it'd be useful and would help performance, but it seems much more disruptive. It requires users to discover it exists, actively adopt a different style of ingesting data, etc. For a 10%-ish gain in a PL. I strongly suggest making this design effort a separate thread, and focusing on the SPI improvements that give "free" no-user-action performance boosts here. -- Craig Ringer http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers