Using the backup procedure to perform an online backup

The SYSCS_UTIL.SYSCS_BACKUP_DATABASE procedure locks the database so that any connection trying to write to the database will be frozen until the backup completes. Database reads can continue while the backup is running.

The SYSCS_UTIL.SYSCS_BACKUP_DATABASE procedure takes a string argument that represents the location in which to back up the database. Typically, you provide the full path to the backup directory. (Relative paths are interpreted as relative to the current directory, not to the derby.system.home directory.)

For example, to specify a backup location of c:/mybackups/2005-06-01 for a database that is currently open, use the following statement (forward slashes are used as path separators in SQL commands):

CALL SYSCS_UTIL.SYSCS_BACKUP_DATABASE('c:/mybackups/2005-06-01')

The SYSCS_UTIL.SYSCS_BACKUP_DATABASE() procedure puts the database into a state in which it can be safely copied, then copies the entire original database directory (including data files, online transaction log files, and jar files) to the specified backup directory. Files that are not within the original database directory (for example, derby.properties) are not copied.

The following example shows how to back up a database to a directory with a name that reflects the current date:

public static void backUpDatabase(Connection conn)throws SQLException
{
// Get today's date as a string:
java.text.SimpleDateFormat todaysDate = 
   new java.text.SimpleDateFormat("yyyy-MM-dd");
String backupdirectory = "c:/mybacksup/" +
   todaysDate.format((java.util.Calendar.getInstance()).getTime());

CallableStatement cs = conn.prepareCall("CALL SYSCS_UTIL.SYSCS_BACKUP_DATABASE(?)"); 
cs.setString(1, backupdirectory);
cs.execute(); 
cs.close();
System.out.println("backed up database to "+backupdirectory);
}

For a database that was backed up on 2005-06-01, the previous commands copy the current database to a directory of the same name in c:/mybackups/2005-06-01.

Uncommitted transactions do not appear in the backed-up database.

Note: Do not back up different databases with the same name to the same backup directory. If a database of the same name already exists in the backup directory, it is assumed to be an older version and is overwritten.