The default behavior of the interface DLL is for applications to wait for completion of each database request before carrying
out other functions. This behavior can be changed using request management functions. For example, when using Interactive
SQL, the operating system is still active while Interactive SQL is waiting for a response from the database and Interactive
SQL carries out some tasks in that time.
You can achieve application activity while a database request is in progress by providing a callback function. In this callback
function, you must not do another database request except db_cancel_request. You can use the db_is_working function in your
message handlers to determine if you have a database request in progress.
The db_register_a_callback function is used to register your application callback functions.
The db_backup function provides support for online backup in embedded SQL applications. The backup utility makes use of this
function. You should only need to write a program to use this function if your backup requirements are not satisfied by the
SQL Anywhere backup utility.
BACKUP statement is recommended
Although this function provides one way to add backup features to an application, the recommended way to do this task is to
use the BACKUP statement. See BACKUP statement.
You can also access the backup utility directly using the Database Tools DBBackup function. See DBBackup function.