| java.lang.Object
 com.db4o.tools.Defragment
| Defragment | | public class Defragment (Code) | | old Deframent source code, now replaced by the built-in functionality in com.db4o.defragment.Defragment.
This class is deprecated. Please use
com.db4o.defragment.Defragment .
This class is delivered as sourcecode in the
path ../com/db4o/tools/
Prerequites:
- The database file may not be
in use.
- All stored classes need to be available.
- If you use yor own special
Db4o translators, they need to be installed before starting Defragment.
Performed tasks:
- Free filespace is removed.
- Deleted IDs are
removed.
- Unavailable classes are removed.
- Unavailable class members are
removed.
- Class indices are restored.
- Previous rename tasks are removed.
Backup:
Defragment creates a backup file with the name [filename].bak. If
a file with this name is already present, Defragment will not run
for safety reasons.
Recommendations:
- Keep the backup copy of your database file.
- Always back up your class files with your database files also.
You will need them to restore the full data of all objects from old database file versions.
- Scan the output log for "Class not available" messages.
You may also run this task programmatically on a scheduled basis.
In this case note that Defragment modifies db4o
configuration parameters. You may have to restore them for your
application. See the private methods Defragment#configureDb4o() and
Db4o#restoreConfiguration() in the sourcecode of
com.db4o.tools.Defragment.java for the exact changed parameters that
may need to be restored.
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| Method Summary | |
| public static void | main(String[] args)
the main method that runs Defragment. | | public void | run(String filename, boolean forceBackupDelete)
programmatic interface to run Defragment with a forced delete of a possible
old Defragment backup.
This method is supplied for regression tests only. | | public static void | setSecondClass(String className)
allows to specify a class to be treated as "second class".
Second class objects are not migrated to the new database on their own. |
| Defragment | | public Defragment()(Code) | | the main method is the only entry point
|
| main | | public static void main(String[] args)(Code) | | the main method that runs Defragment.
Parameters:
args - a String array of length 1, with the name of the databasefile as element 0. |
| run | | public void run(String filename, boolean forceBackupDelete)(Code) | | programmatic interface to run Defragment with a forced delete of a possible
old Defragment backup.
This method is supplied for regression tests only. It is not recommended
to be used by application programmers.
Parameters:
filename - the database file.
Parameters:
forceBackupDelete - forces deleting an old backup. Not recommended. |
| setSecondClass | | public static void setSecondClass(String className)(Code) | | allows to specify a class to be treated as "second class".
Second class objects are not migrated to the new database on their own. A second
class objects is only migrated, if it is referenced by another object.
Parameters:
className - the fully qualified classname, including the package name for Java, including the namespaces and assembly name for .NET. Format examples:
Java: 'com.db4o.f1.Pilot'
.NET: 'com.db4o.f1.Pilot, MyAssembly' |
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