Berkeley DB: db_dump
Полезная информация

db_dump


db_dump [-dN] [-f output] db_file
db_dump [-p] [-f output] [-h home] db_file
db_dump185 [-p] [-f output] db_file

Description

The db_dump utility reads the database file db_file and writes it to the standard output using a portable flat-text format understood by the db_load utility. The argument db_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 and 1.86.

The options are as follows:

-d
Dump the specified database in a format helpful for debugging the Berkeley DB library routines. The output format of the -d option is not standard and may change, without notice, between releases of the Berkeley DB library.

-f
Write to the specified file instead of to the standard output.

-h
Specify a home directory for the database. As Berkeley DB versions before 2.0 did not support the concept of a database home, db_dump185 does not support this option.

-N
Don't acquire shared region locks while searching the database. This option is intended only for debugging and should not be used under any other circumstances.

-p
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.

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 information.

The db_dump and db_dump185 utility output formats are documented in the Dump Output Formats section of the Reference Guide.

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.

Environment Variables

DB_HOME
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 in db_appinit.

See Also

db_archive, db_checkpoint, db_deadlock, db_dump, db_load, db_recover, and db_stat.