TECHNIQUES FOR USING ZONE MAP INFORMATION FOR POST INDEX ACCESS PRUNING

摘要

Techniques for using zone map information for post index access pruning. In one embodiment, for example, a method for using zone map information for post index access pruning comprises: receiving a query statement comprising a first filter predicate on an indexed column of a database table and a second filter predicate on a zoned column of a database table; identifying zero or more pruneable zones of a zone map based on a value for the zoned column in the second filter predicate; obtaining a set of data record addresses from an index on the indexed column based on a value for the indexed column in the first filter predicate; and pruning, from access paths for processing the query statement, any data records, corresponding to data record addresses in the set of data record addresses, that are physically located in one of the pruneable zones.

主权项

1. A method for using zone map information for post index access pruning comprising:
receiving a query statement comprising a first filter predicate on an indexed column of a database table and a second filter predicate on a zoned column of a database table; identifying one or more pruneable zones of a zone map based on a value for the zoned column in the second filter predicate; obtaining a set of data record addresses from an index on the indexed column based on a value for the indexed column in the first filter predicate; and pruning, from access paths for processing the query statement, any data records, corresponding to data record addresses in the set of data record addresses, that are physically located in one of the pruneable zones.