This subsection describes how to modify the HiRDB system definitions. Note that $PDDIR/conf is the directory that stores the unit control information definition file. $PDCONFPATH is the directory that stores other HiRDB system definition files.

To modify the HiRDB system definitions:

1. Create subdirectories under $PDDIR/conf and $PDCONFPATH. In this example, a subdirectory called work is created.
2. Copy the unit control information definition file to $PDDIR/conf/work. Copy other HiRDB system definition files to $PDCONFPATH/work.
3. Modify the HiRDB system definitions that have been copied to $PDDIR/conf/work and $PDCONFPATH/work.
4. Use the pdconfchk -d work command to check the content of the HiRDB system definitions in $PDDIR/conf/work and $PDCONFPATH/work. If any error is found, correct the HiRDB system definition and re-execute the pdconfchk command.
5. Use the pdstop command to normally terminate HiRDB.
6. Use the pdlogunld command to unload the system log files that are waiting to be unloaded.
7. Replace the HiRDB system definition file by copying the HiRDB system definition file modified in step 3 to $PDDIR/conf or $PDCONFPATH.
8. If you modify the specified values of the following operands, you must use the pdloginit command to initialize the system log file.
   pd_log_dual
   pdstart
   
9. Use the pdstart command to normally start HiRDB.

If you use the system reconfiguration command (pdchgconf command), you can modify the HiRDB system definitions while HiRDB is running, and therefore you need not normally terminate HiRDB. Note however that HiRDB Advanced High Availability is required for using this command.

To modify the HiRDB system definition using the system reconfiguration command:

1. Create the $PDDIR/conf/chgconf directory.
2. Copy the HiRDB system definition file being used to the directory created in step 1.
3. Modify the HiRDB system definitions in $PDDIR/conf/chgconf.
4. Use the pdconfchk -d chgconf command to check the HiRDB system definitions in $PDDIR/conf/chgconf. If any error is found, correct the HiRDB system definition and re-execute the pdconfchk command.
5. Use the pdchgconf command to replace the HiRDB system definition with the modified one.
   When you execute the pdchgconf command, the HiRDB system definition file being used (unmodified one) is saved to $PDDIR/conf/backconf. Then, the modified HiRDB system definition file in $PDDIR/conf/chgconf is copied to $PDDIR/conf.
   

Notes:

• If a transaction or utility continues to be active for 15 minutes or longer after the pdchgconf command is input, the command is aborted.
• Some limits apply when you use the system reconfiguration command to modify the HiRDB system definitions. For details about these limits, see the HiRDB Version 9 System Operation Guide.

• When a modification is made to a system common definition, the identical modification must be made to the system common definitions at all server machines.
• If some of the units are abnormally terminated during normal or planned termination of HiRDB, do not modify the HiRDB system definition before restarting HiRDB. If it is modified, HiRDB will not start. Even if HiRDB starts, it cannot run normally after the startup.
• For a HiRDB parallel server configuration, create subdirectories under $PDDIR/conf and $PDCONFPATH for each unit, and check the content of the HiRDB system definitions.
• HiRDB system definitions must not be modified or deleted while they are being used by an active HiRDB. If such a definition is modified or deleted, the operation of the HiRDB cannot be guaranteed.
• Once a planned, forced, or abnormal termination of HiRDB occurs, some of the HiRDB system definition operands cannot be modified; for details, see 1.4 List of operands or the operand explanations for the various definition statements.
• After you have modified the HiRDB system definitions, back up the files located in $PDDIR/conf. To guard against errors in the disk containing the HiRDB directory, back up the files in the HiRDB directory (files in $PDDIR/conf). To restore the HiRDB directory, you need the backup of the files in $PDDIR/conf. Also back up $PDCONFPATH if it is located under the HiRDB directory.
• Note the following when using the standby-less system switchover (1:1) facility: Before modifying the HiRDB system definitions of a normal BES unit, first use the pdstop -u command to normally terminate the normal BES unit and the alternate BES unit. After modifying the HiRDB system definitions, copy both the unit control information definition file and back-end server definition file of the normal BES unit to the alternate BES unit. For details, see the section Creating HiRDB system definitions (system switchover) in the HiRDB Version 9 System Operation Guide.

Before the operands listed below are added, modified, or deleted, HiRDB Datareplicator must be terminated; HiRDB Datareplicator can be restarted after the operand addition, modification, or deletion operation is completed:

• pd_log_dual
• pd_log_max_data_size
• pdlogadfg -d sys
• pdlogadpf -d sys

If these operands are added, modified, or deleted while HiRDB Datareplicator is running, extraction by HiRDB Datareplicator might fail under some circumstances.