{{damfile [-{d|n[-f]}] [-c] logical-file-name physical-file-name}}

Specify the names of the logical file and physical file to be accessed using the DAM service on-line. The DAM service controls access according to the specified logical file name.

-d

Performs deferred updating of the specified file. If this operand is omitted, no deferred updating takes place. (Instead, the DAM file is real-updated at a synchronous point.)

If both a DAM file for which deferred updating is specified and a DAM file for which normal updating is specified are updated and output, they are real-updated at a synchronous point.

-n

Specify this option if the specified files are processed as a file not to be recovered.

-f

Specify this option to perform cacheless access for the specified file. This option must be specified together with the -n option.

-c

Specify this option to continue the normal startup processing of the DAM service even if an error occurs in the specified DAM file. If the normal startup processing of the DAM service cannot continue, it ends. When the DAM service starts, the applicable DAM file is shut down due to the error. When you use dc_dam_open() to access the file, an error is returned with DCDAMER_OHOLD. To use the DAM file that has an error in a UAP, use the damrm command to disconnect the file from online processing, eliminate the cause of the error, and then use the damadd command to register the file for online processing.

logical-file-name~<1-8 character identifier>

Specify a logical file name.

physical-file-name~<1-63 digit path name>

Specify the complete path name as the name of the physical file corresponding to the logical file name. No environment variables can be used.

• The DAM service compares the following two values and uses the greater value as the maximum block length of the DAM file:
  
  • Block length of the file with the largest block length, from among the logical files defined in the damfile definition command
  • Value specified in the dam_max_block_size operand
  If no logical file is defined in the damfile definition command and the dam_max_block_size operand is not specified, the maximum block length of the DAM file is 504 bytes.
  
• The maximum block length of the DAM file in the OpenTP1 system is assumed by the DAM service. The DAM service assumes the block length in the logical file that has the largest block length, from among the logical files defined in the damfile definition command in the DAM service definition. If no logical file is defined in the DAM service definition, the maximum block length is 504 bytes.
• When you specify the -f option, the DAM file data area in the special shared memory for the DAM service is not used and I/O operations are always performed for the file. Therefore, depending on the number of blocks in the DAM file to be accessed while the system is online, the performance may degrade. When you specify cacheless access for all the DAM files used online, you can specify 10 for the dam_cache_size_fix operand to start the system with the minimum DAM cache memory. For some cautionary notes on this type of operation, see the section on the dam_cache_size_fix operand.
• If the total of the number of damfile definition commands and the value specified in the dam_added_file operand exceeds 3600, the DAM service might not be able to start.