Plurrrr

In this post, I want to explain how DNS resolvers work in a different way – with a short Go program that does the same thing described in the comic. The main function (resolve) is actually just 20 lines, including comments.

Postgres supports three types for "schemaless" data: JSON (added in 9.2), JSONB (added in 9.4), and HSTORE (added in 8.2 as an extension). Unfortunately, the performance of queries of all three gets substantially slower (2-10×) for values larger than about 2 kiB, due to how Postgres stores long variable-length data (TOAST). The same performance cliff applies to any variable-length types, like TEXT and BYTEA. This article contains some quick-and-dirty benchmark results to explore how Postgres's performance changes for the "schemaless" data types when they become large. My conclusion is that you should expect a 2-10× slower queries once a row gets larger than Postgres's 2 kiB limit.

grep is one of the most universal and commonly-used commands on the command line. I count about 50 flags you can use on it in my man page. So which ones are the ones you should know about for everyday use?