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Extending PostgreSQL with high level languages (and cats)

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In a recent post we extolled the virtues of creating your own brand new operators in PostgreSQL. SELECT =^_^= FROM happycats; That’s well and good, but the output was a little lacklustre, returning “meow” for every tuple. We’d like to make it more interesting, and one way to add interesting functionality to Postgres is to embed a procedural language. This lets you juggle data with a little more finesse when it comes to certain operations, compared to the usual relational algebra. We’re going to use Perl because it’s easy to integrate with Postgres, and is generally a quick and dirty way to Get Stuff Done. When embedded in Postgres it’s referred to as PL/Perl. Let’s get started. We begin by “installing” the language into the database in which we wish…

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Extending PostgreSQL for fun: with cats

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Perhaps you’ve thought I wish I had more cats in my Postgres database before. We certainly have. Just the other day we were lamenting some of the differences between MySQL and PostgreSQL, particularly the way that MySQL has case-insensitive matching using the LIKE operator, while Postgres has LIKE and ILIKE. This got us thinking, it’d be amusing to have more vague (and hilariously unwieldy) operators, such as: SELECT * FROM foo WHERE a VAGUELY RESEMBLES b; Something like this isn’t too implausible. It’s similar to what a full-text search entails, but it’s far from trivial. This got us thinking: if we can’t easily do that, can we at least have some amusing query syntax? Yes we can!

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How to explain Hash DoS to your parents by using cats

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We came across this interesting article recently, it’s about how an attacker can perform a denial-of-service attack by feeding perverse input to a system that uses weak hashing algorithms. This is referred to as a Hash DoS, and the specific target mentioned in the article is btrfs. btrfs is a next-gen filesystem that’s expected to replace ext3/4 in Linux. It’s still considered experimental but is quite usable and maturing fast. This article piqued our interest because we’re using btrfs “for reals” here at Anchor. It’s well and good to say that, but the article isn’t very exciting unless you have a background in computer science. How would you explain Hash DoS to your parents, who probably don’t have a CompSci background? This is the internet, so the answer is cats….

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