Complex conditions can prevent index usage. Range joins are expensive. Consider denormalization or materialized views for frequently used complex joins.

Index all columns in join conditions

Put equality conditions before range conditions

Avoid functions on join columns

Consider computed columns with indexes

Use covering indexes when possible

Test different condition orders

Using functions on indexed columns

Not indexing all join condition columns

Complex conditions preventing index usage

Cartesian product from too-loose conditions

Not testing performance with real data volumes