Syntax options:
DBKEY SCOPE IS ATTACH | DBKEY SCOPE IS TRANSACTION
Controls when the database key of a deleted row can be used again
by SQL. This setting is not a database root file parameter, but
a characteristic of the implicit database attach executed by
the CREATE DATABASE statement. Thus, the DBKEY SCOPE clause in a
CREATE DATABASE statement takes effect only for the duration of
the session of the user who entered the statement.
o The default DBKEY SCOPE IS TRANSACTION means that SQL can
reuse the database key of a deleted table row (to refer to a
newly inserted row) as soon as the transaction that deleted
the original row completes with a COMMIT statement. (If the
user who deleted the original row enters a ROLLBACK statement,
then the database key for that row cannot be used again by
SQL.)
During the connection of the user who entered the CREATE
DATABASE statement, the DBKEY SCOPE IS TRANSACTION clause
specifies that a database key is guaranteed to refer to the
same row only within a particular transaction.
o The DBKEY SCOPE IS ATTACH clause means that SQL cannot use the
database key again (to refer to a newly inserted row) until
all users who have attached with DBKEY SCOPE IS ATTACH have
detached from the database.
Also it only requires one process to attach with DBKEY
SCOPE IS ATTACH to force all database users to assume this
characteristic.
o Oracle Corporation recommends using DBKEY SCOPE IS TRANSACTION
to prevent excessive consumption of storage area space by
overhead needed to support DBKEY SCOPE IS ATTACH, and to
prevent performance problems when storing new rows.
During the connection of the user who entered the CREATE
DATABASE statement, the DBKEY SCOPE IS ATTACH clause specifies
that a database key is guaranteed to refer to the same row
until the user detaches from the database.
For more information, see the DBKEY HELP topic.