| 摘要 |
A method and system is provided for processing queries. Specifically, techniques are provided for handling a query that does not reference a particular materialized view, where the query requires access to values from a particular column not contained in the materialized view. A technique is also provided for processing a query that does not reference a particular materialized aggregate view, where the materialized aggregate view specifies an outer join between a child table and a parent table and the query specifies a particular type of join between the child table and the parent table, where the particular type of join is one of an inner join, an anti-join and a semi-join. The query is rewritten to produce a rewritten query that accesses the materialized aggregate view to produce data required by the query. A technique is also provided for processing a query that does not reference a particular materialized view and that specifies that results are to be grouped by a first set of one or more columns, where the materialized view reflects data that is grouped by a second set of one or more columns. If each column in the first set of columns either exactly matches a column in the second set of columns, is functionally dependent on another column in the first set of columns, or is functionally dependent on a column in the second set of columns, then the query is rewritten to produce a rewritten query that references the materialized view.
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