Oracle TimesTen In-Memory Database Classic Overview
TimesTen Classic1 is a memory-optimized relational database that provides applications with extremely fast response time and very high throughput as required by many applications in a wide range of industries.
TimesTen Classic delivers real-time performance by changing the assumptions around where data resides at runtime. By managing data in memory, and optimizing data structures and access algorithms accordingly, database operations execute with maximum efficiency, achieving dramatic gains in responsiveness and throughput, even compared to a fully cached disk-based RDBMS. TimesTen Classic can be embedded within the applications to further improve performance of database operations by eliminating inter-process communication and network overheads.
TimesTen Classic is commonly deployed with multi-user and multi-threaded applications using row-level locking and read-committed isolation. Applications access TimesTen databases using standard SQL via JDBC, ODBC, ODP.NET, OCI (Oracle Call Interface), Pro*C/C++, and Oracle PL/SQL programming interfaces. While the best response time is achieved with TimesTen running in-process with the application (also known as "direct mode"), conventional client/server access is commonly used when a database is shared by several applications running on different servers.
TimesTen databases are persistent and recoverable. Durability is achieved through a combination of transaction logging and database checkpointing to disk.
High Availability is provided using TimesTen Classic Replication to replicate transactions between TimesTen databases in real-time. Due to the mission-critical nature of TimesTen applications, most enterprise deployments use TimesTen Replication for availability and disaster recovery. For example, telecommunications and web-accessible global systems such as online-charging, subscriber session management, eCommerce online stores, travel and reservation websites cannot tolerate application/service downtime; financial services and securities trading systems must remain continuously available while financial markets are open.
TimesTen Classic Replication uses memory-optimized, transaction log-based replication technology with an efficient stream-based network protocol for high performance, reliability, and robustness. Key features include:
- Asynchronous replication; provides maximum performance by decoupling application transaction execution from the capture, propagation and apply steps of replication.
- Synchronous replication; provides a higher level of data protection by maintaining full consistency between the active and standby databases; an application commit only returns when the replicated transaction has been both received and committed on the standby database.
- Hot read availability of the standby database; additional read capacity can be provided by configuring additional read-only subscribers.
- Parallel replication for applications that require very high transaction throughput.
- Automated failure detection and failover to the standby database; achieved by seamless integration with Oracle Clusterware.
- Online upgrades; allowing individual servers to be taken offline for software upgrades, while other servers continue uninterrupted.
For applications with existing data already residing in an Oracle database, caching a performance-critical subset of the data into the TimesTen in-memory database is a practical solution to improve application transaction response time. Refer to the TimesTen Application-Tier Database Cache Overview here.
1Note: TimesTen Classic support was reintroduced starting in the 220.127.116.11.0 release.