Archive for November, 2014

3 November, 2014

PgConf.EU recap

by gorthx

I’m safely home from PgConf.EU. Madrid at this time of year was glorious, particularly to this Portlander. (I came home to a steady 12*C and rainy for the next week or … so ;))

We had over 300 attendees, making this the biggest Postgres conference to date, I hear. Of course, I couldn’t get to every talk I wanted (does that ever happen?), but here are some highlights:

Performance Archaeology was a thorough review of how Postgres performance has improved (or not) from version to version. I’m a sucker for benchmarks, and it makes me very happy that Tomas Vondra did this work :)

“Who’s the Fairest of Them All? Pg Interface Performance Comparison” was good from an informational standpoint (ODBC pretty much sucks) but also from a test design standpoint (hey, a valid use case for a Cartesian join!) Most relevant tip for me: complaints about db performance usually turn out to be caused by running queries returning one row at a time, one connection each – and usually from an ORM.

The demo of 3D rendering from Vincent Picavet’s “PostGIS Latest News” looked very promising. There’s a docker container available on his github; make sure you follow the setup instructions. I’m also excited about SP-GiST, spatial GiST indexes, which will provide faster reads and is 3X faster to build. It’s a WIP, and so far it only works on points.

XoF’s talk on “Finding and Repairing Data Corruption” covered some case histories from PgExperts. You all know I like the “war stories”; one thing I like especially about XoF’s talks is he includes “oh yeah, btw, don’t do [x] to try to fix this because you’ll make things worse”. Additional recommendation: disable autovacuum while you’re debugging corruption, because you don’t want it kicking off & changing things.

As usual, Simon and Alvaro packed a ton of info into “Locks Unpicked”. The most immediately useful tip for me was how to avoid the ACCESS EXCLUSIVE lock when adding an FK; do it in two steps: 1. ALTER TABLE [blahdeblah] NOT VALID 2. ALTER TABLE [blahdeblah] VALIDATE CONSTRAINT.

I didn’t get to attend Dimitri’s “You Better Have Tested Backups”, but I was in on a rehearsal. My reaction can be summed up with “You had to do what?!” If this talk didn’t scare you, I don’t know what will.

Craig Ringer’s talk about usability started with a round of “Error Message Jeopardy”, and included a reminder that we were all new once, and have forgotten how much we know. I personally accidentally tried to run psql on a -FC pg_dump just last week, and really appreciate the addition of the HINT message! I also hadn’t heard about the update problems on Yosemite.

Stephen Frost’s “Hacking Postgres” was one of my favorites. We got a tour of the source tree, backend components, and some background about the community coding conventions. (“Programming in Postgres may not always be standard C.”)
General advice:
– check the mailing list for people working on similar problems
– create your patch as a context diff or git –diff
– read your actual patch before you submit it, just in case you did something dorky.

Don’t forget to post your slides & leave conference and speaker feedback.

It was wonderful meeting people I’ve only known from the mailing lists & IRC. (For example.) Thanks very much to the PgConf.EU and SPI for helping me out! I hope to see you next year in Vienna.