SET LOCK MODE
Defines the behavior of the program that tries to access a locked row or table.
Syntax
SET LOCK MODE TO { NOT WAIT | WAIT[ seconds ] }Usage
The SET LOCK MODE instruction
defines the timeout for lock acquisition for the current connection.
When possible, the underlying database driver sets the corresponding connection parameter to define the timeout for lock acquisition. But some database servers may not support setting the lock timeout parameter. In this case, the runtime system generates an exception.
When
using the NOT WAIT clause, the timeout is set to
zero. If the resource is locked, the database server ends
the operation immediately and raises an exception with the
SQL error.
seconds defines the number of seconds to wait for lock acquisition. If the resource is locked, the database server ends the operation after the elapsed time and raises an exception with the SQL error.
When using the WAIT clause
without a number of seconds, the database server waits for lock acquisition
for an infinite time.
With most database servers, the default is to wait for locks to be released.
Make sure that the database server and corresponding database driver both support a lock acquisition timeout option, otherwise the program will raise an exception.
Example
MAIN
DATABASE stock
SET LOCK MODE TO WAIT 20
...
END MAIN