1. Introduction
  2. TimesTen Architecture
  3. Cached Data

Cached Data

When you cache portions of an Oracle database in a TimesTen database, a cache group is created to hold the cached data.

A cache group is a collection of one or more tables arranged in a logical hierarchy by using primary key and foreign key relationships. Each table in a cache group is related to an Oracle database table. A cache table can contain all rows and columns or a subset of the rows and columns in the related Oracle database table. You can create or modify cache groups by using SQL statements or by using Oracle SQL Developer. Cache groups support these features:

  • Applications can read from and write to cache groups.

  • Cache groups can be refreshed from the Oracle database automatically or manually.

  • Updates to cache groups can be propagated to the Oracle database tables automatically or manually.

  • Changes to either the Oracle database tables or the cache group can be tracked automatically.

When rows in a cache group are updated by applications, the corresponding rows in the Oracle database tables can be updated synchronously as part of the same transaction or asynchronously immediately afterward depending on the type of cache group. The asynchronous configuration produces significantly higher throughput and much faster application response times.

Changes that originate in the Oracle database tables are refreshed into the cache by the cache agent.

See Caching in TimesTen.