ASA Database Administration Guide
  Backup and Data Recovery
    Backup and recovery tasks

Making a backup, deleting the original transaction log

If your database is not involved in replication, and if you have limited disk space on your online machine, you can delete the contents of the online transaction log (truncate the log) when you make a backup. In this case, you need to use every backup copy made since the last full backup during recovery from media failure on the database file.

For more information about when to use this type of backup, see A backup scheme for databases not involved in replication.

To make a backup, deleting the transaction log (Sybase Central)

1. Start Sybase Central. Connect to the database as a user with DBA authority.

2. Right-click the database and choose Create Backup Images from the popup menu. The Create Backup Images wizard appears.

3. Click Next on the introductory page of the wizard.

4. Select the database that you want to back up.

5. On the next page, enter the name of a directory to hold the backup copies, and choose whether to carry out a complete backup (all database files) or an incremental backup (transaction log file only).

6. On the next page, select the option Truncate The Transaction Log.

7. Click Finish to start the backup.

To make a backup, deleting the transaction log (SQL)

• Use the BACKUP statement with the following clauses:

  BACKUP DATABASE
  DIRECTORY backup_directory
  [ TRANSACTION LOG ONLY ]
  TRANSACTION LOG TRUNCATE

  Include the TRANSACTION LOG ONLY clause only if you are making an incremental backup.

  The backup copies of the transaction log and database file are placed in backup_directory. If you enter a path, it is relative to the working directory of the database server, not your client application.

To make a backup, deleting the transaction log (Command line)

• From the command prompt, enter the following command:

  dbbackup -c "connection_string" -x [ -t ] backup_directory

  Include the -t option only if you are making an incremental backup.

  The backup copies of the transaction log and database file are placed in backup_directory. If you enter a path, it is relative to the directory from which you run the command.

Notes 

Before the online transaction log can be erased, all outstanding transactions must terminate. If there are outstanding transactions, your backup cannot complete. For information, see Backup internals.

You can determine which connection has an outstanding transaction using the sa_conn_info system procedure. If necessary, you can disconnect the user with a DROP CONNECTION statement.

For more information, see Determining which connection has an outstanding transaction.