HG_DELETE_METHOD option

Specifies the algorithm used during a delete in a HG index.

0 to 3

DBA permissions are not required to set this option. Can be set temporary, for an individual connection, or for the PUBLIC group. Takes effect immediately.

0

This option chooses the algorithm used by the HG index during a delete operation. The cost model considers the CPU related costs as well as I/O related costs in selecting the appropriate delete algorithm. The cost model takes into account:

• Rows deleted

• Index size

• Width of index data type

• Cardinality of index data

• Available temporary cache

• Machine related I/O and CPU characteristics

• Available CPUs and threads

• Referential integrity costs

To force a “small” method, set this option to 1. To force the “large” method, set the option to 2. To force a “midsize” method, set the option to 3.