I am happy to announce a new version of Groundhog, a library for fast high-level database access: http://hackage.haskell.org/package/groundhog http://hackage.haskell.org/package/groundhog-th http://hackage.haskell.org/package/groundhog-postgresql http://hackage.haskell.org/package/groundhog-sqlite Groundhog has been completely overhauled since the last release. Notably, it got support for PostgreSQL and natural foreign keys. I believe that it is a big step forward as this brings more flexibility to the design of the relational schemas while keeping the applications independent of the storage layer. Some of the solutions, particularly schema migration were based on Persistent code. Please see examples at http://github.com/lykahb/groundhog/tree/master/examples. Features: * Support for Sqlite and PostgreSQL. * Natural and composite foreign keys. Earlier it was possible to reference an entity only by the mandatory integer primary key. Now an entity can have several keys including autoincrement primary key (optional) and unique keys which have one or more columns. * Full support of embedded datatypes. You can access a field that contains an embedded datatype as a whole, or access some of the inner subfields individually. This powerful mechanism has allowed implementation of the composite keys, and can be used in future to work with PostgreSQL composite types or MongoDB embedded documents. Instead of serializing value to string, the Groundhog backends flatten tree of embedded datatypes to db columns. * Projections. You can choose what columns to query from a table in a type-safe manner. * Initialization and migration of database schema. * Sum types and polymorphic types. * Expression DSL for use in queries. * Basic list support. * YAML-based settings mechanism. It separates datatype definition and description which facilitates modularity. The settings are inferred from the analysis of the difinition, and overridden with values set by user. The Criterion benchmarks are available at http://lykahb.github.com/groundhog/SqliteBench.html and http://lykahb.github.com/groundhog/PostgreSQLBench.html. Future plans: * Support for joins * Database indexes * Investigate options for implementing MongoDB and MySQL backends Your feedback, suggestions for improvement and criticism are welcome. -- Regards, Boris