Apache Derby vs IBM solidDB comparison

Apache Derby, an Apache DB subproject, is an open source relational database implemented entirely in Java and available under the Apache License, Version 2.0. Some key advantages include:

• Derby has a small footprint -- about 2.6 megabytes for the base engine and embedded JDBC driver.
• Derby is based on the Java, JDBC, and SQL standards.
• Derby provides an embedded JDBC driver that lets you embed Derby in any Java-based solution.
• Derby also supports the more familiar client/server mode with the Derby Network Client JDBC driver and Derby Network Server.
• Derby is easy to install, deploy, and use.

IBM solidDB is a relational database server that combines the high performance of in-memory tables with the nearly unlimited capacity of disk-based tables.

Pure in-memory databases are fast, but strictly limited by the size of memory. Pure disk-based databases allow nearly unlimited amounts of storage, but their performance is dominated by disk access. Even if the computer has enough memory to store the entire database in memory buffers, database servers that are designed for disk-based tables can be slow because the data structures that are optimal for disk-based tables are far from being optimal for in-memory tables. The solidDB solution is to provide a single hybrid database server that contains two optimized engines inside it:

• The main-memory engine (MME) is optimized for in-memory access.
• The disk-based engine (DBE) is optimized for disk-based access.

Both engines coexist inside the same server process, and a single SQL statement can access data from both engines.