To support continuous operation, you can rename user table fields while the database is running. Learn how to rename fields and how field renaming affects transactional concurrency and connected clients.

Renaming a database field no longer requires an exclusive schema lock or disconnecting users from the database. When a user table field is renamed, all connected ABL clients are notified of the change.

This functionality is specific to ABL clients in this release of OpenEdge. When a field is renamed, the ABL client that executes the change checks to see if any earlier versions of the ABL client are connected to the database. If the client finds an earlier version, then the process is treated as an offline operation.

How renaming a field affects ABL clients

After the ABL client renames a field on an active database, a notification is sent to all the other connected clients that a field has been renamed. The connected clients then complete the database transactions in process. When the transactions are completed, the clients can refresh their cache.

Effects on transactional concurrency

Renaming a field online has the following effects on the concurrency of database transactions:
  • Concurrent schema changes are not allowed.
  • New database connection requests are not allowed while a field rename is in process. These requests must be terminated or wait until the transaction completes.
  • Concurrent transactions cannot read schema data. Read operations fail or are blocked until the rename change completes.
Methods for renaming fields online
Use one of the following options to rename a field:
  • Data Administration—Select the Add new objects online checkbox in the Load Data Definitions dialog box to perform the loading operation online. Use this option only to load a delta .df file when there is a difference between two databases (a source database and a target database).

    For more information, see Navigate within the Data Administration tool in Windows in Database Administration Tools.

  • ABL—Directly update the corresponding schema records. The AVM manages these changes internally.
    Use the following ABL procedure to rename a field. 
    FIND FIRST _File WHERE _File-name = 'table name'.
						FIND FIRST _Field WHERE _Field._Field-Name='column name' 
						AND _Field._File-recid = RECID(_File).
						UPDATE _Field._Field-Name='New name'.