Set oriented operations in Postgres

set oriented non procedural data processing

[rubenbla]

Hi all:

Someone knows how to perform set oriented operations in Postgres? That is, instead of processing rows with a cursor sequentially, performing an UPDATE, DELETE or INSERT in a complete set of rows, all at the same time.

I'm looking for something like this:
[codeproject.com ]

I'm having a hard time searching for information on this subjetc. I'll appreciate any help or guidance.

Thanks in advance.
Ruben.