The time, in seconds, of how often a client polls for notification of a schema change. The default is 0, indicating that no polling occurs. The minimum non-zero value is 1; the maximum is 86400 (for 24 hours).
Use Database Client Notification (-usernotifytime) to specify how often a client polls the database to see if a schema change is in process.
If no updates to schema are anticipated, due to index activation or rebuild, while the database is online, you can disable notification, or set the notification value to a very high number. If a change is required, the time between polls can be modified with PROMON or through the _DbParams VST. However, if the value is changed from 0 to a non-zero value, currently connected clients will not observe the change; only new clients will poll to receive the polltime value.