The SQL Anywhere synchronization client, dbmlsync, provides an optional set of event hooks that you can use to customize the synchronization process. When a hook is implemented, it is called at a specific point in the synchronization process.
You implement an event hook by creating a SQL stored procedure with a specific name. Most event-hook stored procedures are executed on the same connection as the synchronization itself.
You can use event hooks to log and handle synchronization events. For example, you can schedule synchronizations based on logical events, retry connection failures, or handle errors and referential integrity violations.
In addition, you can use event hooks to synchronize subsets of data that cannot be easily defined in a publication. For example, you can synchronize data in a temporary table by writing one event hook procedure to copy data from the temporary table to a permanent table prior to the synchronization and another to copy the data back afterwards.
The integrity of the synchronization process relies on a sequence of built-in transactions. Thus, you must not perform an implicit or explicit commit or rollback within your event-hook procedures.
Also, changing connection settings in a hook may produce unexpected results. If you need to change connection settings in a hook, the hook should restore the old value before the hook completes.
You can use client event hooks with the dbmlsync command line utility or any programming interface used to synchronize SQL Anywhere clients, including the Dbmlsync Integration Component and the DBTools interface for dbmlsync.
See Customizing dbmlsync synchronization.
Synchronization event hook sequence
Using event-hook procedures