1. Cache Guide
  2. Methods for Transmitting Changes Between TimesTen and Oracle Databases
  3. Automatically Refreshing a Cache Group
  4. AUTOREFRESH Cache Group Attribute Overview
  5. Restrictions for Autorefresh

Restrictions for Autorefresh

There are restrictions when using the AUTOREFRESH cache group attribute.

  • TimesTen Scaleout only supports static read-only cache groups with incremental autorefresh. See Using Cache Groups in TimesTen Scaleout in the Oracle TimesTen In-Memory Database Scaleout User's Guide.

  • A FLUSH CACHE GROUP statement cannot be issued on the cache group.

    See Flushing a User Managed Cache Group.

  • A TRUNCATE TABLE statement issued on a cached Oracle Database table is not automatically refreshed to the TimesTen cache table. Before issuing a TRUNCATE TABLE statement on a cached Oracle Database table, use an ALTER CACHE GROUP statement to change the autorefresh state of the cache group that contains the cache table to PAUSED.

    See Altering a Cache Group to Change the AUTOREFRESH Mode, Interval or State.

    After issuing the TRUNCATE TABLE statement on the cached Oracle Database table, use a REFRESH CACHE GROUP statement to manually refresh the cache group.

  • A LOAD CACHE GROUP statement can only be issued if the cache tables are empty, unless the cache group is dynamic.

    See Manually Loading and Refreshing a Cache Group and Creating a Dynamic Cache Group with the DYNAMIC Keyword.

  • The autorefresh state must be PAUSED before you can issue a LOAD CACHE GROUP statement on the cache group, unless the cache group is dynamic. If the cache group is dynamic, the autorefresh state must be PAUSED or ON.

  • The LOAD CACHE GROUP statement cannot contain a WHERE clause, unless the cache group is dynamic. If the cache group is dynamic, the WHERE clause must be followed by a COMMIT EVERY n ROWS clause.

    See Using a WHERE Clause.

  • The autorefresh state must be PAUSED before you can issue a REFRESH CACHE GROUP statement on the cache group. The REFRESH CACHE GROUP statement cannot contain a WHERE clause.

  • All tables and columns referenced in WHERE clauses when creating, loading or unloading the cache group must be fully qualified. For example:

    owner.table_name and owner.table_name.column_name

  • To use the AUTOREFRESH cache group attribute in a user managed cache group, all of the cache tables must be specified with the PROPAGATE cache table attribute or all of the cache tables must be specified the READONLY cache table attribute.

  • You cannot specify the AUTOREFRESH cache group attribute in a user managed cache group that contains cache tables that explicitly use the NOT PROPAGATE cache table attribute.

  • The AUTOREFRESH cache table attribute cannot be used when caching Oracle Database materialized views in a user managed cache group.

  • LRU aging cannot be specified on the cache group, unless the cache group is dynamic where LRU aging is defined by default.

    See LRU Aging in TimesTen Classic.

  • If you want to use replication with a static cache group with autorefresh on TimesTen Classic, you can only use an active standby pair replication scheme. Any other type of replication scheme is not allowed with a static cache group with autorefresh on TimesTen Classic.