Use the following procedure when downgrading from a 12.5.4 Adaptive Server that has not been configured for encrypted columns.
Start the 12.5.4 server in single-user mode to guarantee that no other user can access Adaptive Server while you are going through the downgrade steps. See the Utility Guide for details on starting the server in single user mode.
A user with sso_role and sa_role must execute:
sp_encryption remove_catalog
This stored procedure removes the new columns added in syscolumns from each database. If sp_encryption is successful in removing the new columns from syscolumns, it also removes the record of the upgrade item from sysattributes in each database. If a database is unavailable, the command prints an error message and exits. You should bring the unavailable database online and execute sp_encryption remove_catalog again.
Drop the system stored procedure sp_encryption from the sybsystemprocs database.
Shut down the server. You can now use a 12.5.x Adaptive Server binary from a pre-12.5.4 version.
Copy the RUN_SERVER file to a 12.5.x release area and modify it to use the data server binary from the 12.5.x release area.
Restart the server using the modified RUN_SERVER file.
Run the 12.5.x version of installmaster to return system stored procedures to their original version.
