User Guide

SAP AG November 2002
OPTIM_OR_DISTINCT
The special database parameter [Page 80] OPTIM_OR_DISTINCT denotes how the
optimization algorithm changes if you are using OR search conditions in SQL statements.
• Low OPTIM_OR_DISTINCT values: You should use low values for OR search conditions
if you want DISTINCT hitlists where no lines are duplicated.
• High OPTIM_OR_DISTINCT values: You should use high values for OR search
conditions if you do not want DISTINCT hitlists.
REQUEST_TIMEOUT
The special database parameter [Page 80] REQUEST_TIMEOUT denotes the maximum
amount of time (in seconds) you should have to wait for a lock [Page
140] to be released.
This database parameter limits the amount of time you have to wait until a lock is lifted by
other users for all database sessions [Page
135].
If a lock request cannot be satisfied within the time thus defined, a message is returned to the
waiting database session.
RESTART_SHUTDOWN
The general database parameter [Page 79] RESTART_SHUTDOWN determines whether
database instance [Page 132] modes should be changed automatically or not.
The database parameter only takes effect if you are using a Windows operating system (NT,
2000, XP).
• Manual
: All changes to the mode of the database instance must be initiated by the DBA
[Page 137].
• Auto:
The following changes are made to the database instance automatically:
The Windows Service Manager switches the database instance straight to operating
mode [Page 145] ONLINE when it starts.
A database instance in ONLINE mode will be shut down automatically if the operating
system shuts down.
Since the shutdown of an operating system is subject to a time limit, it may
interrupt the automatic shutdown of a database instance, particularly if you are
working with large database instances where a high volume of data is being
changed.
If you restart the database after the shutdown was interrupted, you must import
log entries to restore the database instance. We therefore recommend you set
the database parameter RESTART_SHUTDOWN to manual.
RUNDIRECTORY
The general database parameter [Page 79] RUNDIRECTORY determines which directory is
used as the run directory [Page 147] on the database instance [Page 132].
User Manual: SAP DB 88