17 tips from Oracle9i Performance Tuning Avoiding Problematic Queries

1. Avoid Cartesian products
2. Avoid full table scans on large tables
3. Use SQL standards and conventions to reduce parsing
4. Lack of indexes on columns contained in the WHERE clause
5. Avoid joining too many tables
6. Monitor V$SESSION_LONGOPS to detect long running operations
7. Use hints as appropriate
8. Use the SHARED_CURSOR parameter
9. Use the Rule-based optimizer if I is better than the Cost-based optimizer
10. Avoid unnecessary sorting
11. Monitor index browning (due to deletions; rebuild as necessary)
12. Use compound indexes with care (Do not repeat columns)
13. Monitor query statistics
14. Use different tablespaces for tables and indexes (as a general rule; but the main point is reduce I/O contention)
15. Use table partitioning (and local indexes) when appropriate (partitioning is an extra cost feature)
16. Use literals in the WHERE clause (use bind variables)
17. Keep statistics up to date