A procedure called at a replicate site database to update data at a primary site database is an asynchronous procedure. The procedure performs no action at the replicate site, but rather, the call to the procedure is replicated to the primary site, where a procedure of the same name executes. This is called an asynchronous procedure call (APC). The changes made by the APC are then replicated from the primary to the replicate database in the usual manner.

For information about APCs, see your Replication Server documentation.

The APC_user and APC support

Support for APCs in SQL Anywhere is different from that in Adaptive Server Enterprise. In Adaptive Server Enterprise, each APC executes using the user ID and password of the user who called the procedure at the replicate site. In SQL Anywhere, however, the transaction log does not store the password, and so it is not available at the primary site. To work around this difference, the LTM configuration file holds a single user ID with associated password, and this user ID (the APC_user) executes the procedure at the primary site. The APC_user must, therefore, have appropriate permissions at the primary site for each APC that may be called.