| 摘要 |
Embodiments of the invention provide methods, systems, and articles of manufacture for transforming a physical query (e.g., written in SQL) into an abstract query than can be run against an abstract database described by a database abstraction model. In one embodiment, the transformation occurs as a multiple step process: first, transformation of the physical query into an intermediate representation, such as an abstract query plan, and second, transformation of the intermediate representation into an abstract query. There are thousands upon thousands of existing physical (e.g., SQL) queries. Rather than just abandon these existing queries in favor of an abstract database, embodiments of the present invention provide for reverse query processing, that is, for creating an abstract query of the abstract database from a physical query (e.g., an SQL query) of the physical database underlying the abstraction.
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