Metacat

Technical Details

=================

Metacat is an open source application, and we welcome contributions to the

source from members of the community who are interested in helping out.  This

section will contain a series of technical details about Metacat that will help

contributors understand and extend Metacat.  Much of the detail needed here is

contained in the Administrator's guide, which we will gradually migrate to this

format.

Contents:

.. toctree::

   :maxdepth: 2

   identifiers.txt

Indices and tables

==================

* :ref:`genindex`

* :ref:`modindex`

* :ref:`search`

Metacat: Metadata and Data Management System

================================================

Metacat is a repository for data and metadata (data about data), which helps scientists find, understand and effectively use the data sets they manage or that have been created by others. Thousands of data sets are currently documented in a standardized way and stored in Metacat systems, providing the scientific community with a broad range of ecological data that--because the data are well and consistently described--can be easily searched, compared, merged, or used in other ways.

Not only is the Metacat repository a reliable place to store metadata and data (the database is replicated over a secure connection so that every record is stored on multiple machines and no data is ever lost to technical failures), it provides a user-friendly interface for information entry and retrieval. Scientists can search the repository via the Web using a customizable search form. Searches return results based on user-specified criteria, such as desired geographic coverage, taxonomic coverage, and/or keywords that appear in places such as the data set's title or owner's name. Users need only click a linked search result to open the corresponding data-set documentation in a browser window and discover whom to contact to obtain the data themselves (or how to immediately download the data via the Web).

Metacat's user-friendly Registry application allows data providers to enter data-set documentation into Metacat using a Web form. When the form is submitted, Metacat compiles the provided documentation into the required format and saves it.  Information providers need never work directly with the XML format in which the data are stored or with the database records themselves. In addition, the Metacat application can easily be extended to provide a customized data-entry interface that suits the particular requirements of each project. Metacat users can also choose to enter metadata using the Morpho application, which provides data-entry wizards that guide information providers through the process of documenting each data set.

The metadata stored in Metacat includes all of the information you and others need to understand what the described data are and how to use them: a descriptive data set title; an abstract; the temporal, spatial, and taxonomic coverage of the data; the data collection methods; distribution information; and contact information. Each information provider decides who has access to this information (the public, or just specified users), and whether or not to upload the data set itself with the data documentation.  Information providers can also edit the metadata or delete it from the repository, again using Metacat's straightforward Web interface.

Metacat is a Java servlet application that runs on Window or Linux platforms in conjunction with a database, such as PostgreSQL (or Oracle 8i), and a Web server. The Metacat application stores data in an XML format using Ecological Metadata Language (EML) or another ecological metadata standard. For more information about Metacat or for examples of projects currently using Metacat, please see http://knb.ecoinformatics.org.

   :maxdepth: 1

   development.txt