If true, each time when a connection is taken from the pool, it is checked for validity. If the connection is not valid, it is destroyed and a new one is created.
If this parameter is true, the connection pool manager background validation is disabled in this case as it is not needed. In such case we always have a valid connection, however the performance is not optimal.
This behaviour may be useful when the physical connection is unstable and connection can be lost in a short period of time. Pool manager validates pool connections every 30 seconds, so it is possible that connection will become invalid during this interval and the application will take it from the pool before the validation. If the physical connection is stable, pool manager validation is enough to ensure that the connection is valid, so it is better not to use this property. Use this property only if necessary because it causes a round-trip to the database to validate each connection immediately before it is provided to the application.