Groonga is a fast and accurate full text search engine based on an inverted index. Newly registered document instantly appears in search results, and updates are allowed without read locks. These characteristics result in superior performance for real-time applications. It is also a column-oriented database management system (DBMS). Compared with well-known row-oriented systems, such as MySQL and PostgreSQL, column-oriented systems are more suited for aggregate queries.
DBeaver is a universal database manager and SQL Client. It supports MySQL, PostgreSQL, Oracle, DB2, MSSQL, Sybase, Mimer, HSQLDB, SQLite, Derby, and any database that has a JDBC driver. It is a GUI program that allows you to view the structure of a database, execute SQL queries and scripts, browse and export table data, handle BLOB/CLOB values, modify database meta objects, etc. It has a native UI (provided by the Eclipse SWT library), great performance, and relatively low memory consumption.
ODB is a compiler-based object-relational mapping (ORM) system for C++. It allows you to persist C++ objects to a relational database without having to deal with tables, columns, or SQL and without manually writing any mapping code. The C++ code that performs the conversion between persistent classes and their database representation is automatically generated by the ODB compiler. The ODB compiler is a real C++ compiler except that instead of producing assembly or machine code, it generates portable C++, which can in turn be compiled by any C++ compiler. ODB is not a framework. It does not dictate how you should write your application. Rather, it is designed to fit into your style and architecture by only handling C++ object persistence and not interfering with any other functionality.
hamsterdb Embedded Storage is an embedded database engine written in ANSI-C. It includes B+Trees with variable length keys and records. It supports in-memory databases and endian-independent files, database cursors, multiple databases in one file, "record number" databases, and duplicate keys. hamsterdb is very fast and highly configurable. It compiles and runs on Unix platforms, Linux, Microsoft Windows, and Windows CE.
PostGIS adds support for geographic objects to the PostgreSQL object-relational database. In effect, PostGIS "spatially enables" the PostgreSQL server, allowing it to be used as a backend spatial database for geographic information systems (GIS), much like ESRI's SDE or Oracle's Spatial extension.
MUSCLE (Multi User Server Client Linking Environment) is an N-way messaging server and networking API. It includes client-side networking APIs for various languages, including C, C++, C#, Delphi, Java, and Python. MUSCLE lets programs communicate over a network via streams of serialized Message objects. The included server program ("muscled") lets its clients message each other and store information in its server-side hierarchical database. The database supports flexible queries via hierarchical wildcarding, and "live" updates via a subscription mechanism.
BaseX is a light-weight, high-performance, and scalable XML database system and XPath/XQuery processor, including full support for the W3C Update and Full Text extensions. An interactive and user-friendly GUI frontend gives you great insight into large XML data instances. It is platform independent and works out of the box.