POD Documentation
Tie::DB_File::SplitHash - A wrapper around the DB_File Berkeley database
system
use Tie::DB_File::SplitHash;
[$X =] tie %hash, 'Tie::DB_File::SplitHash', $filename, $flags, $mode, $DB_HASH, $multi_n;
$status = $X->del($key [, $flags]) ;
$status = $X->put($key, $value [, $flags]) ;
$status = $X->get($key, $value [, $flags]) ;
$status = $X->seq($key, $value, $flags) ;
$status = $X->sync([$flags]) ;
$status = $X->fd ;
untie %hash ;
$multi_n determines the 'spread out' or number of files the
hash will be split between. The larger the number, the larger the final
hash can be.
Transparently splits a Berkeley database (DB_File) into multiple files to
allow the exceeding of file system limits on file size. From the outside,
it behaves identically with Berkeley DB hash support in general. This has
the potential to greatly expand the amount of data that can be stored on a
file size limitted file system.
It does so by taking a SHA1 hash of the key to be stored, folding the
resulting hash into a value from 0 to X and storing the data to a db file
selected by the value 0 to X. The randomizing behavior of the SHA1 and
subsequent fold down distribute the records essentially randomly between
the X+1 database files, raising the capacity of the database to (X+1) times
the capacity of a single file database on the average.
NOTE: Using an 'in-memory' database is not supported by this. Use DB_File
directly if you want to do that. Additionally, BTREE and RECNO DBs are not
supported.
- DESTROY;
-
Called when the tied object is being destroyed.
Copyright 1999, Benjamin Franz
(<URL:http://www.nihongo.org/snowhare/>) and FreeRun Technologies,
Inc. (<URL:http://www.freeruntech.com/>). All Rights Reserved. This
software may be copied or redistributed under the same terms as Perl itelf.
Benjamin Franz
Testing.
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