The Optimizer analyzes steps needed to run each query, then chooses the most efficient path that returns answers in the shortest time. The EXPLAIN statement in SQL shows the details of the chosen path, and can be used to further improve query performance. Analyzing complex query plans can be difficult, so Teradata provides the following tools to help:
- Teradata System Emulation Tool (SET), designed to help automate and simplify query plan analysis.
- Query Analysis Tools (DBQAT), designed to improve the overall performance analysis capabilities of Vantage, including the following:
- Query Capture Facility (QCF)
- Database Query Log
- Database Object Use Count
- Target Level Emulation (TLE)