THREAD

Parameter type	Integer
Default value	0
Parameter class	Static
Range of values	0 to the maximum number of enabled threads
Real Application Clusters	If specified, multiple instances must have different values.

THREAD is an Oracle9i Real Application Clusters parameter that specifies the number of the redo thread to be used by an instance.

When you create a database, Oracle creates and enables thread 1 as a public thread (one that can be used by any instance). You must create and enable subsequent threads using the ADD LOGFILE THREAD clause and ENABLE THREAD clause of the ALTER DATABASE statement. The number of threads you create is limited by the MAXINSTANCES parameter specified in the CREATE DATABASE statement.

In exclusive mode, thread 1 is the default thread. However, you can specify THREAD for an instance running in exclusive mode if you want to use the redo log files in a thread other than thread 1.

In parallel mode, you can specify any available redo thread number, as long as that thread number is enabled and is not in use by another instance.

A value of zero specifies that this instance can use any available, enabled public thread.