How does the Informix SQL Optimizer choose which index or table or access method to use when running your SQL? This presentation will focus on how to view and understand the SQL Explain plan to see how your SQL is executed. The SQL Explain plan will provide times for each step in your process.

This presentation will focus on Best Practices for Informix database indexes. Every table should have at least one index, and managing indexes is an integral part of a DBA's task and time. Indexing is one method to optimize the performance of a database by reducing the number of disk reads when a query is executed. An index is a structure which is used to locate and access a row in a database table quickly. Indexes are used to enforce uniqueness, primary, and foreign keys and constraints. Indexes can also be a source of problems in a database and may slow performance down when misused.