Transparency Programs and Macros › IMBSBRDG program module › Converting Records Retrieved from CA IDMS/DB

Converting Records Retrieved from CA IDMS/DB

The IMBSBRDG program converts retrieved CA IDMS/DB records to DBOMP records, reconstructs CA IDMS/DB records from updated DBOMP records, and returns the updated records to the database.

Converting Records

To convert records retrieved from the CA IDMS/DB database, IMBSBRDG performs the following tasks:

• Reads the CA IDMS/DB record into the CA IDMS/DB logical record buffer
• Retrieves the CA IDMS/DB dummy record updated by IMBSPROC
• Moves the pointers for the requested record from the CA IDMS/DB dummy record to the DBOMP file work area (using displacement information in IMBSTAB to determine where to place each pointer)
• Moves segments of data from the CA IDMS/DB logical record buffer to the DBOMP file work area, accounting for the pointers already in place

  Pointer displacement information is used in determining the size of each data segment moved:

  • The size of the first data segment moved equals the number of bytes between the beginning of the DBOMP logical record and the first pointer
  • The size of the second segment moved equals the number of bytes between the first and second pointers
  • This process continues until all of the data in the CA IDMS/DB logical record buffer has been moved into the file work area, where the simulated DBOMP record is available for processing by the calling program

Reconstructing and Returning Records

To reconstruct updated DBOMP records and return them to the CA IDMS/DB database, CA IDMS DML performs the following tasks:

• Moves segments of data from the updated DBOMP logical record in the file work area to the CA IDMS/DB logical record buffer.

  Pointer displacement information is used in determining the size of each data segment:

  • The size of the first segment moved equals the number of bytes between the beginning of the DBOMP record and the first pointer
  • The size of the second segment moved equals the number of bytes between first and second pointers
  • This process continues until all data in the DBOMP logical record (except pointers) has been moved to the CA IDMS/DB logical record buffer.
• Issues a MODIFY command to CA IDMS/DB, returning the updated record in the buffer to the database.

The following two figures illustrate how IMBSBRDG moves data between the CA IDMS logical record buffer and the work area of the DBOMP file.

Transfer from IDMS to DBOMP

The following figure shows the transfer of data from the CA IDMS/DB logical record buffer to the work area of the DBOMP file. Note that when the transfer of data takes place, the pointers already have been moved from the CA IDMS/DB dummy record to the DBOMP file work area.

Transfer from DBOMP to IDMS

This figure shows the transfer of data from the work area of the DBOMP file to the CA IDMS/DB logical record buffer. Note that pointers are not returned with record data to the CA IDMS/DB logical record buffer.

Values Returned to the Calling Program

IMBSBRDG returns values to the calling program, as shown in the following table.