Understanding EclipseLink, 2.7
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NoSQL Platform Concepts

NoSQL is a classification of database systems that do not support the SQL standard.The NoSQL classification can be expanded to include Enterprise Information Systems (EIS) including application databases, legacy databases, messaging systems, and transaction processing monitors, such as IMS, VSAM, and ADABASE.

EclipseLink's NoSQL support includes:

A complete description of EclipseLink support for NoSQL is described in Non-SQL Standard Database Support: NoSQL.

NoSQL and EIS data-sources have a Java Connector Architecture (JCA) resource adapter that supports the Java Connector Architecture Common Client Interface (JCA CCI).

There are many different ways to access NoSQL and EIS data-sources. Many NoSQL data-sources provide a Java API. For EIS data-sources, there are many third party and custom Java adapters. These APIs are normally non-standard, and low-level, similar to JDBC. EclipseLink NoSQL support is built on top of such APIs, and offers the rich, high-level and standard JPA API.

Some NoSQL data-sources support the JDBC API and a subset of the SQL language. Many third-party vendors provide JDBC drivers for EIS data-sources. EclipseLink regular JPA support can be used with any compliant JDBC driver. So, if JDBC access is an option, EclipseLink's NoSQL support is not required, as EclipseLink standard JPA support can be used.

Some NoSQL data-sources may support JCA. JCA is a Java Enterprise Edition API that allows connecting to more generic systems than JDBC. JCA is composed of two parts, a resource adapter layer, and the Common Client Interface (CCI). EclipseLink NoSQL and EIS support is based on the JCA CCI. For MongoDB, Oracle NoSQL, XML files, JMS, and Oracle AQ, EclipseLink provides the JCA adapter and EclipseLink EISPlatform and ConnectionSpec classes. Third party JCA adapters can also be used with EclipseLink as long as they support the CCI. There are third party JCA vendors, such as Attunity, that support various EIS data-sources such as IMS, VSAM and ADABASE.