| 摘要 |
A join plan creates an intermediate table from two or more database tables within a database. In doing so, at least one projected and compressible column within one of the database tables is identified, where the column contains data values to which the application of a compression data transformation results in a reduction in the size of the data values. The frequency of occurrences of at least some unique values in the compressible column is identified, and then the two or more database tables are joined. The results of the join are then stored in the intermediate table such that the compression data transformation is applied to at least some of the unique values in the compressible column for which the frequency has been identified.
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