The Database Services Utility can be started to access the database in either multiple user mode or single user mode.
Multiple user mode is the usual way of running the application server. It permits multiple users to access a DB2 Server for VSE & VM application server simultaneously. Unless you have database maintenance to perform or another task requiring a dedicated database, run the utility with multiple user mode.
DB2 Server for VSE:
For more information about starting the Database Services Utility with multiple user mode, see Multiple User Mode Job Control.
DB2 Server for VM:
The DB2 Server for VM Database Services Utility with multiple user mode cannot run either in the CMS/DOS environment, or in CMS subset.
In preparation for running the Database Services Utility with multiple user mode, initialize the user machine by specifying defaults using the SQLINIT EXEC. On the CMS command line, type:
SQLINIT DBNAME(server-name)
where server-name is the name of the application server to be accessed. Press ENTER.
For more information on the SQLINIT EXEC in multiple user mode, see Running the DB2 Server for VM Database Services Utility with Multiple User Mode.
Run the Database Services Utility with single user mode to prevent concurrent access of a DB2 Server for VSE & VM application server by other users. Unless you have database maintenance to perform, are the sole user of an application server, or are performing a task requiring a dedicated database, run the utility with multiple user mode.
DB2 Server for VSE:
For more information on running the Database Services Utility with single user mode, see Single User Mode Job Control.
DB2 Server for VM:
In DB2 Server for VM single user mode, the SQLINIT EXEC is unnecessary; the Database Services Utility and the application server are executed in the same virtual machine, and you specify the desired application server with the DBNAME parameter of the SQLDBSU EXEC.
For more information on using the SQLDBSU EXEC with single user mode, see Chapter 7, Using the Database Services Utility from Application Programs and SQLDBSU EXEC Format.
| Note: | Because usual operation of the Database Services Utility is with multiple user mode, the task descriptions and procedures in this part of the manual largely address operation of the utility with multiple user mode. |
The Database Services Utility is a general purpose utility that requires two or three files to run: one for Database Services Utility command or SQL statement input, one for message output, and one for data output or input.
The required DB2 Server for VSE input file is the input control card file, and it is assigned to SYSIPT. The input control card file contains utility control commands, which are described in the following section.
The Database Services Utility creates a report; it is assigned to SYSLST. The report lists the input control card file records, messages, and results.
The DB2 Server for VM control file and message file are usually CMS files. You can define the control file to any sequential tape or DASD file supported by CMS OS/QSAM, to a virtual reader file, or to the terminal. You can define the message file to any sequential tape file supported by CMS OS/QSAM, to a virtual print file, or to the terminal.
Often you require an additional file for Database Services Utility input or output. The Database Services Utility commands that use additional files for input or output contain a data definition name (ddname) parameter that you must specify to identify the additional input or output file. In DB2 Server for VSE, the ddname refers to the file name specified in the applicable DLBL or TLBL system control statement. In DB2 Server for VM, this parameter refers to the ddname defined in a CMS FILEDEF command. A ddname can be from one to eight characters. The first character of a ddname must be alphabetic (or a national character). For more information about file definition, see the relevant command description or refer to Appendix B, FILEDEF Command Syntax and Notes.
The required DB2 Server for VM input file is the control file (or command file), and it is assigned to the ddname SYSIN. The control file contains utility control commands, which are described in the following section.
The required DB2 Server for VM output file is the message file; it is assigned to the ddname SYSPRINT. The utility lists the control file records, writes messages, and prints results in the message file.
| Note: | You do not need an additional file when you use the DATALOAD command if you place the data input information in the command file. You do require an additional input or output file with all other commands that have a ddname parameter. |
The Database Services Utility supports the use of multiple-volume tape files and variable-length, spanned records in either environment. For additional information on tape support, refer to the DB2 Server for VM System Administration or the DB2 Server for VSE System Administration manual.