This 30-page paper gives you a basic understanding of the Informix® Dynamic Server (IDS) optimizer, including query rewrite, plan generation, the role of statistics, and optimizer directives.
Summary minor heading
The role of the optimizer component of the IBM Informix Dynamic Server (IDS) is to evaluate possible query execution plans and decide on the best plan based on heuristic rules as well as on cost. This 30-page paper provides a basic understanding of the IDS optimizer.
The paper begins by explaining how the optimizer fits into the SQL engine. It defines terms, then goes into a detailed discussion of the optimization process, including query rewrite, plan generation, explain, directives, and the role of statistics. It also covers distributed query processing, view processing and fragment elimination.
|Article in PDF format||0211desai.pdf||84KB|