If my program crashes with a bsddb (or anydbm) database open, it gets corrupted. How come?

.. note::

The bsddb module is now available as a standalone package `pybsddb

<http://www.jcea.es/programacion/pybsddb.htm>`_.

Databases opened for write access with the bsddb module (and often by the anydbm

module, since it will preferentially use bsddb) must explicitly be closed using

the ``.close()`` method of the database. The underlying library caches database

contents which need to be converted to on-disk form and written.

If you have initialized a new bsddb database but not written anything to it

before the program crashes, you will often wind up with a zero-length file and

encounter an exception the next time the file is opened.

I tried to open Berkeley DB file, but bsddb produces bsddb.error: (22, 'Invalid argument'). Help! How can I restore my data?

.. note::

The bsddb module is now available as a standalone package `pybsddb

<http://www.jcea.es/programacion/pybsddb.htm>`_.

Don't panic! Your data is probably intact. The most frequent cause for the error

is that you tried to open an earlier Berkeley DB file with a later version of

the Berkeley DB library.

Many Linux systems now have all three versions of Berkeley DB available. If you

are migrating from version 1 to a newer version use db_dump185 to dump a plain

text version of the database. If you are migrating from version 2 to version 3

use db2_dump to create a plain text version of the database. In either case,

use db_load to create a new native database for the latest version installed on

your computer. If you have version 3 of Berkeley DB installed, you should be

able to use db2_load to create a native version 2 database.

You should move away from Berkeley DB version 1 files because the hash file code

contains known bugs that can corrupt your data.