This document concerns data modelling and joins
- What is the difference between a join using the join prefix and a join using a SELECT statement?
- When should you join and when shouldn't you? Performance considerations?
- Are there alternatives to joins? (Yes! Applymap!)
- What does the Keep prefix do?
See also my blog post on the same subject: To Join or not to Join.
Joins and Lookups.pdf (199.0 K)