iX V6.5 (30391-90011)

Chapter 4 101

Using the Database

Opening the Database

The DBBEGIN and DBEND intrinsics are used to designate or block logical, static

transactions for logging and recovery purposes. The DBXBEGIN and DBXEND intrinsics are

used to mark logical, dynamic transactions spanning one database, or multiple databases

up to ﬁfteen, for dynamic roll-back recovery. Refer to Table 4-5. later in this chapter for a

deﬁnition of TurboIMAGE/XL transaction types.

In addition to the above intrinsics, log records for DBQUIESCE procedures called by

True-Online Backup to quiesce and unquiesce the database can also be logged to a log ﬁle.

Dynamic roll-back uses the MPE/iX Transaction Management (XM) facility to roll back

transactions online while other database activity is occurring. User logging is not required

for this type of recovery, but is recommended to guard against a hard disk failure. See

chapter 7 for a discussion of logging and recovery methods.