Well, my publisher recently informed me that the book I’ve long been slaving over for almost a year, is finally finished. I must admit that PostgreSQL 9 High Availability Cookbook is somewhat awkward as a title, but that doesn’t detract from the contents. I’d like to discuss primarily why I wrote it.
When Packt first approached me in October of 2013, I was skeptical. I have to admit that I’m not a huge fan of the “cookbook” style they’ve been pushing lately.
Programming is fun. I love programming! Ever since I changed my career from programming to database work, I’ve still occasionally dabbled in my former craft. As such, I believe I can say this with a fair amount of accuracy: programmers don’t understand databases. This isn’t something small, either; there’s a fundamental misunderstanding at play. Unless the coder happens to work primarily with graphics, bulk set-based transformations are not something they’ll generally work with.
When I heard about foreign tables using the new postgres_fdw foreign data wrapper in PostgreSQL 9.3, I was pretty excited. We hadn’t upgraded to 9.3 so I waited until we did before I did any serious testing. Having done more experimentation with it, I have to say I’m somewhat disappointed. Why? Because of how authentication was implemented.
I’m going to get this out of the way now: The postgres_fdw foreign data wrapper only works with hard-coded plain-text passwords, forever the bane of security-conscious IT teams everywhere.
This May, I attended my first international conference: PGCon 2014. Though the schedule spanned from May 20th to May 23rd, I came primarily for the talks. Then there was the Unconference on the 24th. I’d never heard of such a thing, but it was billed as a good way to network and find out what community members want from PostgreSQL. After attending the Unconference, I must admit I’m exceptionally glad it exists; it’s something I believe every strong Open Source project needs.
PostgreSQL is a pretty good database, and I enjoy working with it. However, there is an implementation detail that not everyone knows about, which can drastically affect table performance. What is this mysterious feature? I am, of course, referring to foreign keys.
Foreign keys are normally a part of good database design, and for good reason. They inform about entity relationships, and they verify, enforce, and maintain those relationships. Yet all of this comes at a cost that might surprise you.
