| 摘要 |
A database system includes object relational tables having at least one complex attribute. The database system also includes an optimizer module that selects a join plan for a given query that specifies a join of multiple tables. If the query includes a function selected from the group consisting of a selection predicate applied on a complex attribute, a projection applied on a complex attribute, and a user-defined data type method, then a join path for the join query is determined based in part on a cost associated with application of the function. Application of the function is performed on one of a base table and a join table depending on which has a lower cardinality. The join table is a result of a join of the base table and another table.
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