Ignite for RDBMS Users
Apache Ignite does not require you as a skilled RDBMS user to learn new APIs if you want to start working with an Ignite cluster. All the data processing and SQL schema definition can be accomplished with a familiar SQL syntax. Ignite complies with SQL ANSI-99 standard supporting all SQL and DML commands, including SELECT, UPDATE, INSERT, MERGE, DELETE statements and distributed joins. It also provides support for a subset of DDL commands relevant for distributed SQL databases.
Ignite can store data and indexes both in memory and on disk which allows executing distributed SQL queries across different memory layers achieving the performance and scale of in-memory computing together with the disk durability and strong consistency in one system. If the persistence is disabled, Ignite can act as a pure in-memory database.
The main difference between Ignite and traditional relational databases is that, first, the memory is treated as a fully functional storage, not just as a caching layer, like most databases do. Second, Ignite is horizontally scalable, highly available and supports both key-value APIs and collocated processing approach.