9.9.1 Deadlock priority value for commands

The deadlock priority value for commands is normally lower than the deadlock priority value for a UAP. Therefore, if deadlock occurs, it is the command that terminates in an error. To prevent commands from terminating in an error, you can set the deadlock priority value for commands to be higher than the deadlock priority value for a UAP. When you increase the command deadlock priority value, the error occurs in the transaction when deadlock occurs.

Organization of this subsection
(1) Commands for which the deadlock priority value can be changed
(2) List of deadlock priority values

(1) Commands for which the deadlock priority value can be changed

You can change the deadlock priority value for the following commands:

(2) List of deadlock priority values

Table 9-3 lists the deadlock priority values.

Table 9-3 Deadlock priority values

Type and conditionDeadlock priority value
UAPValue of PDDLKPRIO in client environment definition9696
6464
3232
OmittedWhen X/Open XA interface is used96
When X/Open XA interface is not used and a distributed server is used for the distributed databases64
Utility64
Commandpdhold -b, pdhold -s, pddbchg, pdorbegin, pdorendValue of pd_command_deadlock_priority*
Other commands64
* You can specify in this operand a deadlock priority value of 32, 64, 96, or 120. If this operand is omitted, the deadlock priority value is either 64 or 120 depending on the type of locked resource.
Reference note
  • A smaller deadlock priority value indicates a higher processing priority, and a larger deadlock priority value indicates a lower processing priority.
  • If two transactions have the same deadlock priority value, the first one that executes is accorded the higher priority.