Free relational software for windows

Lattice.DataMapper is a useful .NET based object persistence library for relational databases. Lattice.DataMapper bridges the gap between objects and data source and allows the developer to work at the object level with little knowledge of the data source. In addition, Lattice.DataMapper shields your business logic from data source schema changes and data source provider changes which benefits maintainability.
The Lattice.DataMapper framework will help you to significantly reduce the amount of .net code that you normally need to access a relation database. Simplicity is the biggest advantage of Lattice.DataMapper over other frameworks and object relational mapping (O/R Mapper) tools. To use Lattice.DataMapper you need only be familiar with XML, stored procedures and SQL. Lattice.DataMapper provides the platform and flexibility to build your own architecture and you, the developer, have the full power of both stored procedures and SQL at your fingertips.
Lattice.DataMapper is a tool that maps .NET objects to and from an underlying relational database using external XML configuration and mapping files. The data access is externalized in XML and can include both SQL queries and stored procedure calls. An API is provided to then dynamically store and retrieve .NET objects using the mapping definitions.
Main features:
- Support .NET 2.0 and .NET 1.1 framework
- Support for different data providers and multiple data sources.
- Support object pre-fetch( one-to-one, one-to-many, many-to-many relationship )
- Queries are batched and run as one transaction
- Batch job can be run asynchronously at scheduled time as separate thread
- Cache can be set up per query ( supports cache database dependency )
- Support .NET 2.0 Generic and nullable value type
- Support nullable value types using null-value attribute
- Logging and error handling using Log4net framework
- Support distributed transactions without deriving from the ServiceComponent
- XML file based configuration file to define available data providers and data sources.
- XML based mapping files to define O/R mapping
- XSLT template based tool to auto-generate stored procedures, business entities and mapping files.

PostgreSQL Database Server 8.4 brings a powerful, perfect and popular relational database system. It has more than 15 years of active development and a proven architecture that has earned it a strong reputation for reliability, data integrity, and correctness. It runs on all major operating systems, including Linux, UNIX (AIX, BSD, HP-UX, SGI IRIX, Mac OS X, Solaris, SunOS, Tru64), BeOS, and Windows. PostgreSQL is an open-source descendant of this original Berkeley code.

If you need a PostgreSQL Database GUI, you can download NAVICAT PostgreSQL. It supports to import CSV, XML or other formats to PostgreSQL. PostgreSQL supports a large part of the SQL: 2003 standard and offers many modern features: complex queries, foreign keys, triggers, views, transactional integrity, and multi-version concurrency control. Also, PostgreSQL can be extended by the user in many ways. Version 8.4 may include unspecified updates, enhancements, or bug fixes.