StorageTek 312564001 User Manual
38
DB2 Manager User Guide
StorageTek
Proprietary
Use: The MAXTRDR parameter specifies the number of active
tape-reader subtasks which are to be created in the DB2
Manager control region.
Manager control region.
Notes: This parameter indirectly controls the maximum number of
tape drives which may be concurrently allocated by the control
region.
region.
If TAPEWAIT=0 is specified, requests which cause this
maximum to be exceeded will receive a “resource busy”
condition from DB2 Manager - an SQL error code of –652 will
be returned to the calling application and field SQLERRD(6) in
the SQLCA will contain the hexadecimal value x’0A’.
condition from DB2 Manager - an SQL error code of –652 will
be returned to the calling application and field SQLERRD(6) in
the SQLCA will contain the hexadecimal value x’0A’.
Non-zero values of TAPEWAIT will cause requests which
encounter this condition to be held internally for processing
until a tape drive becomes available, or until the time limit
specified in the TAPEWAIT parameter is exceeded, at which
point a “resource busy” condition will be returned to the calling
application, as above.
This setting may be varied during DB2 Manager operation via
the 'SET MAXTRDR’ operator command.
until a tape drive becomes available, or until the time limit
specified in the TAPEWAIT parameter is exceeded, at which
point a “resource busy” condition will be returned to the calling
application, as above.
This setting may be varied during DB2 Manager operation via
the 'SET MAXTRDR’ operator command.
If this parameter is omitted, a default value of MAXTRDR=4
will be used.
TAPECNTL: MAXDRDR
MAXDRDR = nnn
Requirement: Optional
Default:
4
Validation: nnn = 1-3 digit numeric value in range 1 - 255
Use: The MAXDRDR parameter specifies the number of active disk-
reader subtasks which are to be created in the DB2 Manager
control region. This is set during control region initialization,
and may be varied thereafter using the ‘SET MAXDRDR’
operator command.
control region. This is set during control region initialization,
and may be varied thereafter using the ‘SET MAXDRDR’
operator command.
Notes: This parameter indirectly controls the maximum number of
Archive Manager ‘K’ copy files which are to be simultaneously
allocated by the DB2 Manager control region for retrieval of
disk-resident objects from Archive Manager.
allocated by the DB2 Manager control region for retrieval of
disk-resident objects from Archive Manager.
Requests for retrieval of an object from an Archive Manager
‘K’ copy file are added to the disk-reader subtask with the
shortest queue length. Increasing the number of disk-reader
subtasks will reduce the average queue length per subtask,
‘K’ copy file are added to the disk-reader subtask with the
shortest queue length. Increasing the number of disk-reader
subtasks will reduce the average queue length per subtask,