The db_dump utility reads the database file file and
writes it to the standard output using a portable flat-text format
understood by the db_load utility. The argument file
must be a file produced using the Berkeley DB library functions.
The db_dump185 utility is similar to the db_dump utility
except that it reads databases in the format used by Berkeley DB versions 1.85
The options are as follows:
Dump the specified database in a format helpful for debugging the Berkeley DB
Display all information.
Display only page headers.
Do not display the free-list or pages on the free list. This
mode is used by the recovery tests.
The output format of the -d option is not standard and may change,
without notice, between releases of the Berkeley DB library.
Write to the specified file instead of to the standard output.
Specify a home directory for the database environment; by
default, the current working directory is used.
Dump record numbers from Queue and Recno databases as keys.
List the databases stored in the file.
Do not acquire shared region locks while running. Other problems such as
potentially fatal errors in Berkeley DB will be ignored as well. This option
is intended only for debugging errors and should not be used under any
If characters in either the key or data items are printing characters (as
defined by isprint(3)), use printing characters in file
to represent them. This option permits users to use standard text editors
and tools to modify the contents of databases.
Note, different systems may have different notions as to what characters
are considered printing characters, and databases dumped in
this manner may be less portable to external systems.
Aggressively salvage data from a possibly corrupt file. The -R
flag differs from the -r option in that it will return all
possible data from the file at the risk of also returning already deleted
or otherwise nonsensical items. Data dumped in this fashion will almost
certainly have to be edited by hand or other means before the data is
ready for re-load into another database
Salvage data from a possibly corrupt file. When used on a uncorrupted
database, this option should return equivalent data to a normal dump, but
most likely in a different order.
Specify a single database to dump. If no database is specified, all
databases in the database file are dumped.
Write the version number to the standard output and exit.
Dumping and reloading Hash databases that use user-defined hash functions
will result in new databases that use the default hash function.
While using the default hash function may not be optimal for the new database,
it will continue to work correctly.
Dumping and reloading Btree databases that use user-defined prefix or
comparison functions will result in new databases that use the default
prefix and comparison functions.
In this case, it is quite likely that the database will be damaged
beyond repair permitting neither record storage or retrieval.
The only available workaround for either case is to modify the sources
for the db_load utility to load the database using the correct
hash, prefix and comparison functions.
The db_dump185 utility may not be available on your system as it
is not always built when the Berkeley DB libraries and utilities are installed.
If you are unable to find it, see your system administrator for further
The db_dump utility may be used with a Berkeley DB environment (as described for the
-h option, the environment variable DB_HOME, or,
because the utility was run in a directory containing a Berkeley DB
environment). In order to avoid environment corruption when using a Berkeley DB
environment, db_dump should always be given the chance to detach from
the environment and exit gracefully. To cause db_dump to release all
environment resources and exit cleanly, send it an interrupt signal
When using an Berkeley DB database environment, the db_dump utility
does not configure for any kind of database locking and so should not
be used with active Berkeley DB environments. If db_dump is used in
an active database environment, corruption may result.
The db_dump utility exits 0 on success, and >0 if an error occurs.
The db_dump185 utility exits 0 on success, and >0 if an error occurs.
If the -h option is not specified and the environment variable
DB_HOME is set, it is used as the path of the database home, as described