Manual Reference Pages - DATA::OBJECTDRIVER::DRIVER::SIMPLEPARTITION (3)
Data::ObjectDriver::Driver::SimplePartition - basic partitioned object driver
use base qw( Data::ObjectDriver::BaseObject );
columns => [ parent_id, partition_id, ... ],
driver => Data::ObjectDriver::Driver::DBI->new( @$GLOBAL_DB_INFO ),
primary_key => parent_id,
number => scalar @PARTITIONS,
get_driver => \&get_driver_by_partition,
use base qw( Data::ObjectDriver::BaseObject );
driver => Data::ObjectDriver::Driver::SimplePartition->new(
using => ParentObject
primary_key => [parent_id, object_id],
Data::ObjectDriver::Driver::SimplePartition is a basic driver for objects
partitioned into separate databases. See
Data::ObjectDriver::Driver::Partition for more about partitioning databases.
SimplePartition helps you partition objects into databases based on their
association with one record of a parent class. If your classes dont meet
the requirements imposed by SimplePartition, you can still write your own
partitioning driver. See Data::ObjectDriver::Driver::Partition.
Often this is used for user partitioning, where the parent class is your user
account class; all records of other classes that are owned by that user are
partitioned into the same database. This allows you to scale horizontally with
the number of users, at the cost of complicating querying multiple users data
SimplePartition will load the related instance of the parent class every
time it needs to find the partition for a related object. Consider using a
minimal mapping class for the parent, keeping as much data as possible in other
related classes. For example, if User were your parent class, you might keep
only the user ID and other data used to find users (such as login name and
email address) in User, keeping further profile data in another
As all the partitioned classes related to a given parent class will share the
same partition_get_driver logic to turn a partition ID into a driver, you
might put the partition_get_driver function in the parent class, or use a
custom subclass of SimplePartition that contains and automatically specifies
the partition_get_driver function.
Creates a new basic partitioning driver for a particular class. The required
members of %params are:
You can also include any further optional parameters you like. They will be
passed to the partitioned classs partition_get_driver function as given.
The name of the parent class on which the driven class is partitioned.
Using a class as a parent partitioned class requires these properties to be defined:
The parent class must have a partition_id column containing a partition
identifier. This identifier is passed to the partition_get_driver function to
identify a driver to return.
The parent classs primary key must be a simple single-column key, and that
column must be the same as the referencing column in the partitioned classes.
The partition_get_driver property must be a function that returns an object
driver, given a partition ID and any extra parameters given to the
This property can also be defined as get_driver in a call to
Class->has_partitions(). See Data::ObjectDriver::BaseObject.
A SimplePartition driver will require these properties to be defined for
Your primary key should be a complex primary key (arrayref) with the simple key
of the parent object for the first field.
using is required.
The using parameter to the SimplePartition constructor is required to
create the partitioned classs get_driver function. Perhaps you omitted it,
or your subclass of SimplePartition did not properly specify it to its
The parent class name you specified in your using parameter does not appear
to be a valid class name. If you are automatically generating parent class
names, check that your method of converting strings to class names is correct.
Failed to load parent class: error
The parent class you specified in your using parameter could not be loaded,
for the given reason. Perhaps you didnt include its location in your library
Partitioning driver not defined for partitioned class
The partitioned class named in the error is configured to use the
SimplePartition driver but does not have a partition_get_driver set.
Check that you intended to use SimplePartition with that class or, if youre
automatically specifying the partition_get_driver function, that your
technique is working correctly.
Cannot extract column from terms search terms or primary key
The SimplePartition driver could not determine from the given search terms
or object key what the ID of the related parent record was. Check that your
columns in the partitioned and parent classes share the same name, and that
your application includes the parent ID in all search() calls for the
partitioned class and instances of partitioned objects before attempting to
Optionaly you can enable a basic support of search across multiple
partition by passing the multi_partition arg (true value) to the search
Member of class with ID parent ID not found
The parent record associated with the partitioned object could not be loaded.
Perhaps your application deleted the parent record without removing its
associated partitioned objects first.
BUGS AND LIMITATIONS
There are no known bugs in this module.
Data::ObjectDriver is free software; you may redistribute it and/or modify
it under the same terms as Perl itself.
AUTHOR & COPYRIGHT
Except where otherwise noted, Data::ObjectDriver is Copyright 2005-2006
Six Apart, email@example.com. All rights reserved.
|perl v5.20.3 ||DATA::OBJECTDRIVER::DRIVER::SIMPLEPARTITION (3) ||2016-01-14 |
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