Server environment and distributed queries

Set the DEADLOCK_TIMEOUT configuration parameter and the PDQPRIORITY environment variable to specify information for distributed queries.

The DEADLOCK_TIMEOUT configuration parameter specifies the maximum number of seconds that a database server thread can wait to acquire a lock. If a distributed transaction is forced to wait longer than the number of seconds specified, the thread that owns the transaction assumes that a multi-server deadlock exists. The following error message is returned:
-143 ISAM error: deadlock detected.

The effective value of PDQPRIORITY for a session is sent to the remote site when a connection is established. Subsequent changes to this parameter in the coordinator are not reflected on the remote site. However, the exact behavior of this environment variable depends on the role of the database server in the distributed query (coordinator or participant).

PDQPRIORITY has different syntax and semantics for different server versions. For information about setting PDQPRIORITY, see the IBM® Informix® Performance Guide for your server.