How to reduce the cost of the ports collection?

[Francisco García Rodríguez <public%francisco-garcia.net@localhost>]

hi,

I am trying to reduce the cost of working with pkgsrc packages collection by 
filtering out packages I am not interested in. A simple make clean from the 
root takes ages, and cvs update also takes its time. 

Basically I wanted to filter out individual ports and/or whole collections 
(audio, finance, games...). First I tried with a CVS ignore file. Modifications 
were ignored but a "cvs update" pulled out the ignored folders.

what do you do to reduce the cost of working with the pkgsrc tree?

kind regards,
Francisco