Materialized View Schema Design Guidelines

Before starting to define and use the various components of summary management,
you should review your schema design to abide by the following guidelines wherever
possible.

Guidelines 1 and 2 are more important than guideline 3. If your schema design does
not follow guidelines 1 and 2, it does not then matter whether it follows guideline 3.
Guidelines 1, 2, and 3 affect both query rewrite performance and materialized view
refresh performance.



If you are concerned with the time required to enable constraints and whether any
constraints might be violated, then use the ENABLE NOVALIDATE with the RELY clause
to turn on constraint checking without validating any of the existing constraints. The risk with this approach is that incorrect query results could occur if any constraints are broken. Therefore, as the designer, you must determine how clean the data is and whether the risk of incorrect results is too great.

Posted in: Materialized Views