TurboIMAGE/XL Database Management System Reference Manual MPE/iX V6.5 (30391-90011)

Chapter 5 147
TurboIMAGE/XL Library Procedures
DBCONTROL
or the database is closed. You can call mode 5 successfully
if the CIUPDATE setting for the database equals ON, but
the call has no impact on the option setting for the current
process unless an intervening call to DBCONTROL mode 6
disabled the option. If the CIUPDATE flag is
DISALLOWED, a call to mode 5 returns an error. The
CIUPDATE option is available only in database access
modes 1, 3, and 4.
Mode 6: Disable the critical item update option. If CIUPDATE has
been set to ON for the database (using DBUTIL>>SET),
mode 6 disables the option for the current DBOPEN until
either a DBCONTROL mode 5 call enables the option or the
database is closed. If the CIUPDATE option setting for the
database equals ALLOWED and the process has called
DBCONTROL in mode 5 to enable the option, then mode 6
disables the option for that same process. The CIUPDATE
option is available only in database access modes 1, 3, and
4.
Mode 7: Allow the database to be included in the dynamic
multiple database transaction (DMDBX). DBCONTROL
mode 7 needs to be done once, for every database, before
including it in DBXBEGIN mode 3 call for DMDBX.Mode7is
used programmatically to allow it for DMDBX and remains
activated until the database is closed or the application
terminates.
Mode 7 also activates the database for deadlock detection.
In case of a deadlock, DBLOCK will return an error, 26,
instead of causing a process hang. Note that mode 7 will
activate both deadlock detection and inclusion in DMDBX.If
you only want deadlock detection and not DMDBX, your
DBXBEGIN call can use mode 1 instead of 3.
Mode 9: Enable the HWMPUT option of DBPUT for the current
DBOPEN. This causes DBPUT to try placing entries at the
high-water mark first instead of at the delete chain head
first.
Mode 10: Disable the HWMPUT option of DBPUT for the current
DBOPEN. This causes DBPUT to try placing entries at the
delete chain head first. This is the default action if
DBCONTROL is not called.
Mode 13: Allow a privileged mode caller to perform B-Tree related
tasks such as adding, dropping, rebuilding, releasing, or
securing a B-Tree index file. Exclusive database access is
required to add, drop, or rebuild a B-Tree index. Qualifier
has a structured record containing dataset information
and directives. Refer to chapter 11, "B-Tree Indices" for
the qualifier layout.