Trafodion is an open-source webscale SQL-on-Hadoop DBMS solution that extends and builds on Apache Hadoop. Its name is the Welsh word for "transactions" (pronounced "Tra-vod-eee-on") because the developers wanted to emphasize the fact that one specific way it extended Hadoop was through guaranteed transactional integrity. By doing so, it targets big data transactional and operational workloads rather than analytic workloads. It is ACID-compliant and has fully-functional ANSI SQL support
Hewlett-Packard Company launched Trafodion as an open-source project in 2014, and a version was released in early 2015 before it became a part of the Apache Incubator in May 2015. In January of 2018, it was established as an Apache Top-Level Project.
Apache Trafodion utilizes the HBase-Trx implementation of Multi-version Concurrency Control (MVCC). This implementation guarantees row-level ACID semantics and only requires row locks for write operations, not read operations.
Since Trafodion is built on top of HBase, it shares HBase's column family data model using key-value pairs.
Foreign key constraints are supported in Trafodion.
Trafodion only supports the READ COMMITTED isolation level.
Trafodion supports hash joins. It is recommended that the number of tables in a join is limited to 64, otherwise the query may not compile.
Trafodion utilizes HBase's Write Ahead Log.
Trafodion fully supports ANSI SQL.
Trafodion is built on top of HBase, which means it shares its disk-oriented storage architecture model from HDFS.
Trafodion uses a single column family to store all columns.
Trafodion allows for stored procedures written in Java and typically compiles with SQL and JRT (Java Routines and Types). The stored procedure itself is a Java method in a JAR file.