IBM DB2 for i

Overview

Key Benefits

Getting Started

Products

Support

With the V5R3 release, DB2 for i announced support for creating and maintaining Materialized Query Tables (MQTs) (also referred to as automatic summary tables or materialized views). On April 29, 2005, query optimizer support was made available which will allow the optimizer to implicitly recognize MQTs and use them when optimizing and running queries, with the goal of improved performance.

To use MQT support, the following PTFs are needed:

• SF99503 (DB Group #4)
• SI17164
• SI17609
• SI17610
• SI17611
• SI17637
• MF34848
• SI17824
• SI17836

Also MQT support requires the setting of two new QAQQINI options, MATERIALIZED_QUERY_TABLE_USAGE and MQTERIALIZED_QUERY_TABLE_REFRESH_AGE.

For information on MQTs, see the following:

• SQL Reference in the V5R3 IBM i and System i Information Center provides information on creating, altering and refreshing MQTs.
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• Database Performance and Query Optimization book provides information on using MQTs and setting the new QAQQINI options.
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• 'The Creation and Use of Materialized Query Tables Within DB2 for i'[White Paper]