We’ve all gotten the dreaded email/call from a user stating that a query is “slow sometimes”. If you’re lucky, the “sometimes” actually ends up being fairly consistent and you can fairly easily determine what’s happening (an errant cron job, for example). All too often though, the issue really is sporadic, fleeting, and indeterministic. So how do you track these down? And more importantly what do you do about them once found?
PostgreSQL has a pretty extensive logging facility. I’ve talked briefly about configuring it to get the most out of pgBadger before, but today I’m gonna talk a bit about the naming of the log file itself. The chosen filename doesn’t have to be static. You can, in fact, have the name dynamically created by using strftime() escapes. But what exactly are those?
Upgrading your PostgreSQL database from one major version (e.g. 9.4.x) to another major version (e.g. 9.5.x) used to a painful and exceedingly slow process. You essentially had two options: dump / reload the data or use one of the complex logical replication tools.
Following on from this post, you probably have multiple versions of PostgreSQL installed on your Mac. In that post, I added an example function to help you manage all these concurrent installs. Today, I’m back with a full-fledged shell script to help manage all this. Without further ado, the script:
Like most geeks, I have scripts that I’ve written that I like to have run from cron on a regular basis. And since the running of these scripts might be in the middle of the night, I like for them to email their output to me so I know if they succeeded or failed. As such, I need an MTA on my computer that can actually deliver these emails to GMail. For me, this is trivial using Sendmail or SSMTP on a Linux box, but I can never remember how to do this using Postfix on OSX. So after having to Google everything to get this running once more, I’m going to commit the steps here for my future self to reference :)