n is either 1 (true) or 0 (false). The default value is 0.
Every TCOMMIT command requests a flush of the journal data involved in that transaction to disk. SynchCommit controls what happens at that point. When enabled (n = 1), TCOMMIT completes after the journal data write operation completes. If SynchCommit is not enabled, TCOMMIT completes without waiting for the write operation.
Changing This Parameter
On the Compatibility page of the Management Portal (System Administration > Configuration > Additional Settings > Compatibility), in the SynchCommit row, click Edit. Select SynchCommit to enable this setting.
Instead of using the Management Portal, you can change SynchCommit in the Config.Miscellanous class (as described in the class reference) or by editing the CPF in a text editor (as described in the Editing the Active CPF section of the “Introduction to the Configuration Parameter File” chapter in this book).