When a database is started under Control Center in multiple user mode all startup parameters are taken from the database PARMS file. Database default values are used for those parameters not specified. When started in single user mode only the parameters listed below are taken from the PARMS file, database default values are used for all others.
Depending on the situation in which a database is being started (to take an archive; certain time of day), certain database parameters can be changed outside of the values specified in the database PARMS file. The exec which controls this is SQMOPARM EXEC. Currently, it checks primarily for certain log mode switches, and archive statuses, and overrides the NCUSERS parm to equal 1. This exec lends itself to user modification for any number of situations (specific database IDs; time of day start-ups; additional messages not currently checked for). The override will occur only when the database is brought up under the pre-defined condition. At other times, the regular database PARMS file is used.