NAME

dw-etl - generate a simple load script

SYNOPSIS

dw-etl [options]

OPTIONS

--dsn

--db_user

--db_password

--fact

The name of the fact table.

--dimension

The name of one or more dimensions.

EXAMPLE

dw-etl --dsn='dbi:SQLite:dbname=test.db' \
       --fact='sales' \
       --dimension='user' \
       --dimension='product'

DESCRIPTION

dw-etl will create the base of a simple load script.

The load script, by default, will read from a tab-separated file containing all the necessary columns for fact and dimensions.

ETL

The load script is the last step of the ETL (extract/transform/load) process.

By now, we expect that the data was extracted from source systems, cleaned and exported to a tab-separated file. (Or any other format you think is convenient.)

The load script will read the input file and load the Data Warehouse database.

SLOWLY CHANGING DIMENSIONS

One of the most important tasks of the load script is to take care of "slowly changing dimensions".

Any dimensional attributes marked with "KEEP_HISTORY" flag will be checked against live data. Any changes to these fields will lead to the creation of a new record.

If you believe that one attribute will change often, consider if it shouldn't have its own dimension?

AUTHOR

Nelson Ferraz, <nferraz at gmail.com>

ACKNOWLEDGEMENTS

LICENSE AND COPYRIGHT

Copyright 2010 Nelson Ferraz.

This program is free software; you can redistribute it and/or modify it under the terms of either: the GNU General Public License as published by the Free Software Foundation; or the Artistic License.

See http://dev.perl.org/licenses/ for more information.