Fix for parallel scans on explain.depesz.com

On Friday, Zr40 reported on irc that explain.depesz.com doesn't show table/index names for Parallel Seq Scan nodes.

Checked it and found couple of other omissions of the same kind with other Parallel* scans.

Fixed (I hope) all of them in:

The change is not really big, but just figured I'll let you know.

explain.depesz.com, paste.depesz.com – TOR announcement and some updates

I assume that you're familiar with explain.depesz.com and paste.depesz.com services.

From today they are also available as services in TOR, using respectively: explain4pg4j5wbw.onion and paste4sql64vzyry.onion (of course you need to have TOR Browser or some other way to browse darknet).

Why I did that? Well, I believe that TOR is one of the greatest inventions ever, and I'd like to do something so that it will be less associated with drugs, porn, or other illegal activities. Don't realistically think that there will be many people using TOR to access my Pg-related services, but it is a thing that I could have done, so I did it.

While working on it, I also updated pgFormatter code under paste-site to newest version.

Continue reading explain.depesz.com, paste.depesz.com – TOR announcement and some updates

New change on explain.depesz.com

Some (long) time ago, someone on irc suggested that I add option to keep track of optimizations of queries.

Sorry, I forgot your name, and the mails disappeared in some crash.

Anyway – right now, when you are on some plan page, you can press “Add optimization" button, and you will be redirected to index page, but when you will add plan there, it will be understood to be plan from optimization of the query. Like this one.

You can have any number of optimizations per plan, and when viewing plan that has optimizations, or is an optimization of earlier plan – you will see this above plan table.

Whether you'll use it – it's up to you. Someone wanted it, and it looked like sensible thing to add, so there it is 🙂

Continue reading New change on explain.depesz.com

A way to share SQL queries – paste.depesz.com

Long time ago I wrote first version of explain.depesz.com. Since then I gradually improve it. But, what was lacking was a way to paste queries too – explain.depesz.com handles explains, but not plain queries.

Now this has changed. I created new site: paste.depesz.com which allows for sharing queries.

Thanks to pgFormatter it also does query pretty-printing (which is not something readily available on other paste sites).

Obviously, code to the site is publicly available in GitHub repo.

Now, goes my request – if you have designer skills, I would greatly appreciate someone that could make the site nicer (prettier, more responsive). My CSS/JS knowledge is pretty limited, and I'm happy anyway about what I did with the look right now, but if you could make it nicer/prettier, that would be amazing.

Have fun, and if you have any feature requests, please post them in here…

Change on explain.depesz.com

As of now, main table that stores explain.depesz.com plans is partitioned.

This shouldn't be, at all, visible for users of the site, but if it would, please let me know (on irc, or via email).

In case you're wondering why, after all there is only ~ 270,000 plans – the reason is very simple. Splitting the data into multiple tables makes maintenance tasks (vacuum, dump) much simpler and easier.

explain.depesz.com – new change and some stats

Quite a long time ago (in October), Oskar Liljeblad reported a bug in anonymization. Namely – group keys were not anonymized.

You can see example of such plan here.

I finally got to it, fixed the bug, pushed new version to live site, and now such plans will be correctly anonymized.

Thanks Oskar, and sorry for long delay.

Continue reading explain.depesz.com – new change and some stats

explain.depesz.com changes and new stats

Some time ago I was contacted by Adam Smith – he pointed out that subquery names in “Subquery Scan" nodes were not properly anonymized.

Now, they are, which you can see in here:

While working on it, I also added (helpful?) links from node types to my blogposts about reading explain output – Explaining the unexplainable.

Continue reading explain.depesz.com changes and new stats

New functionality on explain.depesz.com, and some statistics

Some time ago Karl Bartel asked me to add ability to parse plans that were done using “ANALYZE ON, TIMING OFF". Initially I didn't see the point, but he said that explain.depesz.com allows him to hide parts of the tree, and other columns (aside from actual time) are extracted and presented in more readable way.

OK. Got his point, but was busy. Finally today committed:

Now – plans made using analyze without timing work nicely. In process also fixed display of nodes that never were executed.

And now time for some bragging, a.k.a. statistics:

Continue reading New functionality on explain.depesz.com, and some statistics

Changes in explain.depesz.com

This time the changes do not modify how the website works. But they make it simpler to deploy clone of explain.depesz.com on your own server.

Thanks to Petr A. Korobeinikov I got full automation for setting test/development/internal clones of the site. What was done previously manually, now can be done very fast using Vagrant or Puppet.

Great stuff, thanks Petr.
Continue reading Changes in explain.depesz.com