MetaModel 1.5 released. Unify your view on all datastores

MetaModel 1.5, an Open Source Java framework for accessing, exploring and querying different datastores using a unified API, have just been released. MetaModel provides a single view and a SQL/LINQ-like query engine for everything ranging from relational databases, CSV files, Excel spreadsheets, XML files, dBase (.dbf), MS Access (.mdb) and (.odb) databases.

The 1.5 release has been more than a year under way, including substantial new features and enhancements. Three major themes influence the new features of the 1.5 release:

Improved datastore compliancy

In addition to the already extensive set of supported datastore types, the following new datastore features have been added:

  • Support for Excel 2007+ (.xlsx) spreadsheets has been added.
  • Composite datastores have been added, allowing you to define queries that span multiple datastores.
  • Excel formula calculation have been added.

Fluent Query Builder API

MetaModel 1.5 retains the existing Querying API, which is extremely flexible but also complex, and therefore quite easy to make mistakes with. But MetaModel 1.5 adds a new layer of abstraction to the Querying API: The Query Builder API. With the Query Builder API you can define queries in an even easier, more safe and elegant way. The goal of the Query Builder API is to leverage the use of the compiler as far as possible for query expression.

An example demonstrates it quite well:

DataContext dc = DataContextFactory.create[your_datastore_type]DataContext (...);
Query q = dc.query()

Interfaces and immutability

Instead of the previous JavaBeans based API, the 1.5 release includes interfaces for just about everything in the library. This means that it is as of now easier to test, integrate and deploy MetaModel. It also allows for better encapsulation internally as well as improved safety by exposing only immutable variants of the data structures (like Table, Schema, Column etc.) that are modifiable only by the framework.

Today it was also announced that Human Inference, the European data quality authority has finished their acquisition of the site, to actively enter the market for entry-level Open Source data oriented applications. All projects on, including MetaModel, will remain Open Source, but heavily enforced by the invested time and resources that Human Inference is adding to these projects.

For more information about the acquisition, see the press release on the Human Inference website.

MetaModel is already in use in a lot of projects, including the DataCleaner data analysis/profiling application and Quipu, the data warehouse generator. It is also in Human Inference’s plans to expand the usage of MetaModel into their enterprise-grade data matching and deduplication applications. If you think MetaModel 1.5 sounds interesting, head over to the website to learn more. MetaModel is available as a Maven artifact or as a traditional download at Google code.


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