MySQL: LIKE vs. REGEXP() performance testing

Introduction At some point I needed to choose between using LIKE or REGEXP() for a not so simple string match. Without going into the details, the matching string contains a lot of wildcard segments, and while both would have done the job, I thought maybe REGEXP() would benefit from some extra information about the wildcard [...]

MySQL: Enforcing long unique BLOB / TEXT columns with UNIQUE INDEX

Introduction When creating indexes to TEXT / BLOB columns (and their variants), it’s required to specify how many characters the index should cover. In MySQL’s docs it’s usually suggested to keep them short in for better performance. There’s also a limit on the number of characters, which varies from one database engine to another, going [...]

Decoding email’s quoted-printable with Perl

To make it short, the command at shell prompt is $ perl -MMIME::QuotedPrint -e ‘local $/; $x=<>; print decode_qp($x)’ < quoted.txt > unquoted.html and I needed this to extract an HTML segment of an email.

Pretty-printing data structures with Perl with Data::Dumper

As Perl allows for complicated data structures by virtue of references to hashes and arrays, it’s often useful to look into what’s going on there. In my case, it was on the output of a large JSON parse. So to make a long story short, if $tree is a reference to the data structure, go [...]

Random notes about Gimp 2.10

This is just a few notes to self on this tool. Version 2.10 is a big deal: It’s the first one to use GPU acceleration for scaling and rotation, as well as deforming of different types. No more small previews, no more sluggish response to scaling. No need to scale down images for working, because [...]