Attribute

KeysetCursorOptions (KCO)

Purpose

Determines which columns are used to comprise the keyset that the driver uses to create the initial keyset on which cursor operations are based. Greenplum does not offer a true row identifier column; the driver instead uses two hidden system columns provided by the Greenplum database, ctid and gp_segment_id. Because the database might reassign these IDs following a Vacuum operation, the driver can be configured to also include other columns to help ensure that data integrity is maintained.

Valid Values

0 | 1

Behavior

If set to 1 (RowID and Searchable Columns), the driver uses a combination of every non-LOB column in the Select list and the ctid and gp_segment_id hidden columns to build the keyset. By adding other Select list fields to the keyset, the driver is able to indicate the row cannot be found if the IDs change following a Vacuum operation.

If set to 0 (RowID Columns), the driver uses the ctid and gp_segment_id hidden system columns.

Notes

• This option has no effect unless the Enable Keyset Cursors (EnableKeysetCursors) connection option is enabled.

Default

0

GUI Tab

Advanced tab