Caching with EO

Hi All

Can anybody offer a little help as to a strategy for record access.

I have a table with 28000 records which hold lon lat information to  
which I have to query during a repetition.

For each record in a repetition I need to access a different table  
and pull lon lat for each postcode - this could be up to 100  
simultaneous requests by individual users.

Is it best to set the entity to Cache in Memory and collect objects  
or is it better to collect raw rows?

Any help and advise would be appreciated..

Gino