Originally released commercially in 2002 under GemStone Systems as Gemfire, it was first used in Wall Street trading platforms. In 2010, GemStone Systems was acquired by VMWare and by 2013, Pivotal had spun out of VMWare and took Gemfire with it. Pivotal then proceeded to submit Gemfire to the Apache Incubator in 2015 under the name Geode, and was graduated to a top-level project in 2016.
In a Geode distributed, system, caches are defined as an abstraction that describes the node of the in-memory storage for the data. Each cache contains regions, which data is stored in the form of key-value pairs. So caches are similar to the construct of databases and regions are similar to tables in a relational database.
Read Uncommitted Repeatable Read
Geode supports repeatable reads, but its default allows for dirty reads.
Although Geode doesn't support foreign keys, it provides a similar function called data colocation to store related data entries that have the same ID from different data regions into one single member. For example, the Geode system contains one customer records region and one customer orders region and they are related to each other through the customer. By using colocation, users can maintain all records and orders information for a customer in a cache of a single member, which will be used by all operations regarding this customer only.
http://geode.apache.org/releases/
http://geode.apache.org/releases/latest/javadoc/index.html
Apache
2015
Gemfire
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