(a) Utility execution

• The database structure modification utility (pdmod) can be executed only when HiRDB is running.
• The database structure modification utility (pdmod) should be executed on a server machine where the single-server or the system manager is located.

(b) Control statements

• Multiple control statements can be specified simultaneously. The database structure modification utility completes processing at each control statement. Should any control statement cause an error, the database structure modification utility continues with the processing by skipping that statement. The control statements that have been executed successfully are not rolled back, even when other control statements produced errors. Therefore, if an error occurs in the database structure modification utility, resolve the error based on standard error output and messages that are output to the message log, and re-execute only those control statements that caused an error.
• A comment can be provided in a control statement by enclosing it with a slash-asterisk (/*) and an asterisk-slash (*/).
• If you selected utf-8 as the character encoding in the pdntenv command, you can use a control statements file that contains a BOM. However, only ASCII characters are permitted for comments in the control statements file. If character encoding other than ASCII is used, pdinit may not function correctly.

(a) Utility execution results

The results of execution of the database structure modification utility can be verified by the following methods:

• pddbls command (with -r ALL -a specification)
• Retrieving the dictionary table
• Executing the database condition analysis utility

(b) In the event a HiRDB file system area is corrupted

If the execution of the database structure modification utility is interrupted due to a power failure or the pdkill command, in some cases the HiRDB file system area can be damaged. If a conflict is detected by executing the pdfls command, use one of the following procedures to perform recovery:

• Use the pdfmkfs command to recreate the HiRDB file system area. For each RDAREA, execute the database structure modification utility on the HiRDB files that were stored.
• Execute the pdfbkup and pdfrstr commands to back up and restore the HiRDB file system area.