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(python2.1-lib.info)bsddb

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Interface to Berkeley DB library
================================

Interface to Berkeley DB database library

This manual section was written by Skip Montanaro <skip@mojam.com>.
The `bsddb' module provides an interface to the Berkeley DB library.
Users can create hash, btree or record based library files using the
appropriate open call. Bsddb objects behave generally like
dictionaries.  Keys and values must be strings, however, so to use
other objects as keys or to store other kinds of objects the user must
serialize them somehow, typically using marshal.dumps or pickle.dumps.

There are two incompatible versions of the underlying library.  Version
1.85 is widely available, but has some known bugs.  Version 2 is not
quite as widely used, but does offer some improvements.  The `bsddb'
module uses the 1.85 interface.  Starting with Python 2.0, the
`configure' script can usually determine the version of the library
which is available and build it correctly.  If you have difficulty
getting `configure' to do the right thing, run it with the `--help'
option to get information about additional options that can help.  On
Windows, you will need to define the `HAVE_DB_185_H' macro if you are
building Python from source and using version 2 of the DB library.

The `bsddb' module defines the following functions that create objects
that access the appropriate type of Berkeley DB file.  The first two
arguments of each function are the same.  For ease of portability, only
the first two arguments should be used in most instances.

`hashopen(filename[, flag[, mode[, bsize[, ffactor[, nelem[, cachesize[, hash[, lorder]]]]]]]])'
     Open the hash format file named FILENAME.  The optional FLAG
     identifies the mode used to open the file.  It may be `r' (read
     only), `w' (read-write), `c' (read-write - create if necessary) or
     `n' (read-write - truncate to zero length).  The other arguments
     are rarely used and are just passed to the low-level `dbopen()'
     function.  Consult the Berkeley DB documentation for their use and
     interpretation.

`btopen(filename[, flag[, mode[, btflags[, cachesize[, maxkeypage[, minkeypage[, psize[, lorder]]]]]]]])'
     Open the btree format file named FILENAME.  The optional FLAG
     identifies the mode used to open the file.  It may be `r' (read
     only), `w' (read-write), `c' (read-write - create if necessary) or
     `n' (read-write - truncate to zero length).  The other arguments
     are rarely used and are just passed to the low-level dbopen
     function.  Consult the Berkeley DB documentation for their use and
     interpretation.

`rnopen(filename[, flag[, mode[, rnflags[, cachesize[, psize[, lorder[, reclen[, bval[, bfname]]]]]]]]])'
     Open a DB record format file named FILENAME.  The optional FLAG
     identifies the mode used to open the file.  It may be `r' (read
     only), `w' (read-write), `c' (read-write - create if necessary) or
     `n' (read-write - truncate to zero length).  The other arguments
     are rarely used and are just passed to the low-level dbopen
     function.  Consult the Berkeley DB documentation for their use and
     interpretation.

See also:
     Note: dbhash DBM-style interface to the `bsddb'

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