SQL - Filtering large tables with joins - best practices

Question

I have a table with a lot of data and I need to join it with some other large tables.

Only a small portion of my table is actually relevant for me each time.

Answer 1

In a decent cost based query planner what happens is (your case)

1. join conditions and where conditions are parsed at same level

2. the type of join and statistics determines the path (what happens first) - in such a way that the smallest intermediate results are retrieved (least I/O > fastest query)