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.

On 18th of February, Alvaro Herrera committed patch: Convert Postgres arrays to Perl arrays on PL/perl input arguments   More generally, arrays are turned in Perl array references, and row and composite types are turned into Perl hash references. This is done recursively, in ...

Today, Mattias|farm on IRC asked how to create primary key using HASH index. After some talk, he said that in some books it said that for "=" (equality) hash indexes are better. So, I digged a bit deeper.