The APIs of many database vendors do not permit use of a connection during an asynchronous call in that connection. The DB Interface Module generally clears the connection of pending work before executing the next command, but it doesn't check the connection state. This combination of factors may result in unpredictable behavior for applications using the same connection for multiple asynchronous calls. When this behavior occurs, error messages returned by the server are fielded to the application using the standard error handling model of the DB Interface Module.

We recommend that applications use a unique asynchronous connection for each database call when running many asynchronous calls simultaneously against a database.