Add support for DB2 selectivity clause

Description

DB2 uses a cost based query optimizer based on distribution statistics of the actual data. Unfortunately there is no distribution statistics for geometry attributes. As a consequence, the optimizer is not able to deal with spatial indices correctly.

The full description is here:
http://www.ibm.com/developerworks/data/library/techarticle/dm-0510stolze/

It is possible to give a hint to the optimizer.

should be

The idea is to add a param

to the class DB2NGDataStoreFactory which defaults to FALSE.

If the param is TRUE, the selectivity clause will be used.

Environment

None

Assignee

Christian Mueller

Reporter

Christian Mueller

Triage

None

Components

Fix versions

Affects versions

Priority

High
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