listing a large amount of data

Hello,
I tried to lookup previous posts but couldn't find anything relevant.
I am trying to list a large amount of data that takes ages and may cause the server to timeout. Is there a way that I pre-filter the data dynamically? For example, I have a field 'month' and a field 'year'. Can I make it so that the results are filtered for the current month + year? I will still need to provide access to other filter values for months/years so I cannot do it in the query as a 'permanent' where-clause.
Any ideas would be great.
Regards,
Jim