TimesTen vs Coherence

两者都是Oracle的产品，Chris Jenkins的这段描述要言不烦，直击重点：

These are very different technologies. Coherence is not specifically a cache, though it can be used as one in some circumstances. Coherence is a distributed in-memory object grid designed to help Java/POJO based applications scale. It is not a database, it does not support database concepts or semantics nor does it have a query language. It also does not provide any persistence ‘out of the box’ though you can plug various things into it to provide a persistence capability. If you want to be able to store/retrieve/process Java objects in a scalable and high performance manner with high availability etc. then Coherence is what you want.

TimesTen is a full featured in-memory database. It uses the relational model (tables, indexes etc.) and it’s access language is SQL and it supports PL/SQL. It uses regular database APIs (ODBC, JDBC, OCI, Pro*C, ODP.NET). It provides full persistence and high performance high availability via parallel replication. It also has built in functionality to allow it to act as a cache for an Oracle database.

So, very different technologies with different a`architectures and programming models and targeting different use cases. The ‘best one’ very much depends on your requirements on the context of the differences between the products. It is very rare that both would be equally applicable; normally the above factors make a clear indication for one or the other.

出处：https://community.oracle.com/thread/3882790?sr=stream&ru=477028