History[06][07]

TimesTen was originally named as SmallBase and developed by HP Labs. Shortly after its first commercial use in 1995, the product was split out as a separate startup company and renamed as TimesTen. In 2005, the company with 90 employees at the time was acquired by Oracle. TimesTen was then integrated with Oracle software as well as services and become part of Oracle Database Products.

Checkpoints[08][09]

TimesTen maintains two checkpoint files (ds0 and ds1) on disk to keep track of metadata of in-memory permanent data. It switches two files when a checkpoint is done to ensure there is always at least one completed checkpoint file for backup and recovery purpose. The rate for checkpointing disk writes is configurable by application. It supports fuzzy or non-blocking checkpoints as well as transaction-consistent checkpoints (i.e. blocking checkpoints).

Compression[08]

TimesTen supports columnar compression. This feature uses dictionary-based encoding to replace column values with dictionary table identifiers. It maintains separate dictionary for each column.

Concurrency Control

Data Model

Indexes

By default TimesTen uses B+Tree. The original version (SmallBase) from the 1990s supported T-Trees. TimesTen still supports T-Tree indexes but the administrator has to request for the DBMS to use them.

Isolation Levels

Query Interface

Storage Architecture

Stored Procedures[10]

System Architecture

Views