Chapter 9. Query Rewrite
In Chapter 7, we described materialized views, which can be used to precompute and store results of frequently used queries. A major benefit of doing this is that you can use query rewrite to transparently rewrite queries to use these materialized views, thus significantly reducing the query response time. With this feature, queries that used to take hours to return results can now return them in minutes or even instantly.
As with indexes, materialized views and query rewrite should be considered an essential part of query tuning in a data warehouse. Just as the query optimizer considers all available indexes when determining the fastest way to answer the query, it also considers any available materialized views that may ...
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