On 19th of January, Robert Haas committed patch: Use abbreviated keys for faster sorting of text datums. This commit extends the SortSupport infrastructure to allow operator classes the option to provide abbreviated representations of Datums; in the case of text, we abbreviate by taking ...

In previous post in the series I wrote about how to interpret single line in explain analyze output, it's structure, and later on described all basic data-getting operations (nodes in explain tree). Today, we'll move towards more complicated operations.

Every so often someone asks why sorting behaves irrational. Like here: $ select string from test order by string; string ---------- dean deer de luca depesz de vil dyslexia (6 rows) Why aren't "de luca" and "de vil" together?

On 4th of December, Tom Lane committed really cool patch: KNNGIST, otherwise known as order-by-operator support for GIST. This commit represents a rather heavily editorialized version of Teodor's builtin_knngist_itself-0.8.2 and builtin_knngist_proc-0.8.1 patches. I redid the opclass API to add a separate Distance method instead ...

March 12th, 2009 by depesz | Tags: , , , , , , | 6 comments »

I had this interesting case at work. We have imports of objects. Each object in import file has its "ID" (which can be any string). Same "ID" is in database. So the idea is pretty simple - we can/should check how ...

August 31st, 2007 by depesz | Tags: , , , , | 3 comments »

faber4 on irc asked about how to get ascii-based sorting, while his postgresql was initdb'ed with utf-8 based locale (en_US.UTF-8 to be exact). what can we do about it?