NAME
ORLite::Mirror - Extend ORLite to support remote SQLite databases
SYNOPSIS
# Regular ORLite on a readonly SQLite database
use ORLite 'path/mydb.sqlite';
# The equivalent for a remote (optionally compressed) SQLite database
use ORLite::Mirror 'http://myserver/path/mydb.sqlite.gz';
# All available additional options specified
use ORLite::Mirror {
url => 'http://myserver/path/mydb.sqlite.gz',
maxage => 3600,
show_progress => 1,
env_proxy => 1,
prune => 1,
index => [
'table1.column1',
'table1.column2',
],
};
DESCRIPTION
ORLite provides a readonly ORM API when it loads a readonly SQLite
database from your local system.
By combining this capability with LWP, ORLite::Mirror goes one step
better and allows you to load a SQLite database from any arbitrary URI
in readonly form as well.
As demonstrated in the synopsis above, you using ORLite::Mirror in the
same way, but provide a URL instead of a file name.
If the URL explicitly ends with a '.gz' or '.bz2' then ORLite::Mirror
will decompress the file before loading it.
OPTIONS
ORLite::Mirror adds an extensive set of options to those provided by the
underlying ORLite library.
url
The compulsory "url" parameter should be a string containing the remote
location of the SQLite database we will be mirroring.
ORLite::Mirror supports downloading the database compressed, and then
transparently decompressing the file locally. Compression support is
controlled by the extension on the remote database.
The extensions ".gz" (for gunzip) and ".bz2" (for bunzip2) are currently
supported.
maxage
The optional "maxage" parameter controls how often ORLite::Mirror should
check the remote server to see if the data has been updated.
This allows programs using the database to start quickly the majority of
the time, but continue to receive automatic updates periodically.
The value is the number of integer seconds we should avoid checking the
remote server for. The default is 86400 seconds (one 24 hour day).
show_progress
The optional "show_progress" parameter will be passed through to the
underlying LWP::UserAgent that will fetch the remote database file.
When set to true, it causes a progress bar to be displayed on the
terminal as the database file is downloaded.
env_proxy
The optional "env_proxy" parameter will be passed through to the
underlying LWP::UserAgent that will fetch the remote database file.
When set to true, it causes LWP::UserAgent to read the location of a
proxy server from the environment.
prune
The optional "prune" parameter should be used when the surrounding
program wants to avoid leaving files on the host system.
It causes any files or directories created during the operation of
ORLite::Mirror to be deleted on program exit at "END"-time.
index
One challenge when distributing SQLite database is the quantity of data
store on disk to support the indexes on your database.
For a moderately indexed database where all primary and foreign key
columns have indexes, the amount of data in the indexes can be nearly as
large as the data stored for the tables themselves.
Because each user of the database module will be interested in different
things, the indexes that the original creator chooses to place on the
database may not even be used at all and other valuable indexes may not
exist at all.
To allow sufficiently flexibility, we recommend that SQLite database be
distributed without any indexes. This greatly reduces the file size and
download time for the database file.
The optional "index" parameter should then be used by each different
consumer of that module to index just the columns that are of specific
interest and will be used in the queries that will be run on the
database.
The value should be set to an "ARRAY" reference containing a list of
column names in "tablename.columnname" form.
index => [
'table1.column1',
'table1.column2',
],
SUPPORT
Bugs should be reported via the CPAN bug tracker at
<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=ORLite-Mirror>
For other issues, contact the author.
AUTHOR
Adam Kennedy <adamk@cpan.org>
COPYRIGHT
Copyright 2008 - 2012 Adam Kennedy.
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
The full text of the license can be found in the LICENSE file included
with this module.