TurboIMAGE/XL Database Management System Reference Manual (30391-90012)

Chapter 7 325
Logging and Recovery
Logging Preparation
NEWACCT command for a new account, or the ALTACCT command for an existing account,
as follows:
:NEWACCT acctname,mgrname ;CAP= capability list (include LG)
:ALTACCT acctname ;CAP= capability list (include LG)
Next, the account manager can provide logging capability to individual users by using the
NEWUSER command for new users, or the ALTUSER command for an existing user, as
follows:
:NEWUSER username; CAP= capability list (include LG)
:ALTUSER username; CAP= capability list (include LG)
For example:
:NEWACCT CAPE,RICK;CAP=LG,AM,AL,GL,SF,ND,IA,BA
:NEWUSER ILSA;CAP=LG,AL,GL,SF,ND,IA,BA
Refer to the MPE/iX Commands Reference Manual for information on other MPE/iX user
logging commands, including these listed here:
RELLOG Removes a log identifier.
ALTLOG Alters an existing log identifier.
LISTLOG Lists the current log identifiers.
Any messages that are followed by (ULOGERR#) or (ULOGMSG#) are MPE/iX errors or
system messages.
Step 3--Logging to Tape or Disk
You must choose whether to log to tape or disk. The overhead required by the logging
operation is comparable on disk or tape. However, other factors should be considered.
For roll-back recovery when logging to tape, the database must be in the system volume
set. For roll-back recovery when logging to disk, the database and the log file must be in
the same volume set. Logging to tape is the more secure option, because a log file residing
on tape is less susceptible to damage from possible system failure than a disk log file. Refer
to appendix G for more information on considerations when logging to disk and tape.
For allocating resources, logging to tape requires that the system be able to make a tape
drive available as long as the database is accessible for modification. If the decision is
made to log to disk, you must use the MPE/iX BUILD command to create a new file and
allocate space on disk, as described in step 4. This allocation must be generous enough to
avoid any possibility of filling the log file to capacity.