Your data seems not that big, please double check your join case.
However try to do QVD optimized load, you can see drastic improvement in performance. If you use any transformations or where clauses while loading it won't comes under optimized load, so try. to avoid them.
If you still need to apply transformations and where clauses while loading- use temp tables, resident tables, where exist clauses to achieve the need.
Your application is based on two QVDs the should be joined by a single common column (you did not elaborate about their join), these are some performance enhancement tips for you:
- Memory, for the size of your application, 8 GB is good, 16 GB is better, 32 GB fantastic.
- If the two tables are joined on a single column, and this column is not numeric, implement the AUTONUMBER function.
- Your solution should not have synthetic keys, with data from two QVDs this is unlikely, but anyhow, something to check.
- There are more tips on John Whiterspoon reply here