About Moving to a Different Patch Release by Modifying the Instance

This section contains information about moving to a different patch release of TimesTen by modifying the TimesTen instance. Moving to a different patch release includes upgrades and downgrades. See "Moving to a Different Patch Release Using ttBackup and ttRestore" for information on moving to a different patch release using backup and restore operations.

Concepts that are important when moving to a different patch release:

• Start a database: The subdaemon either creates a new shared memory segment or re-attaches to an existing one. These operations are used to start a database:

  • Load: The subdaemon creates a new shared memory segment, and loads the contents of the most recent checkpoint file into this new shared memory segment.

  • Remap: The subdaemon re-attaches to an existing shared memory segment.

• Stop a database: The subdaemon disconnects from the shared memory segment and either destroys the shared memory segment or preserves it. These operations are used to stop a database:

  • Unload (clean): The shared memory segment is written to the checkpoint file on disk (by performing a static checkpoint operation). The subdaemon disconnects from and destroys the shared memory segment. The load operation starts the database.

  • Detach (clean): The shared memory segment is optionally written to the checkpoint file on disk (by performing a static checkpoint operation). The subdaemon disconnects from the shared memory segment, but does not destroy it. The shared memory segment remains in memory. The remap operation starts the database.

Note:

For a complete list of the operations you use to start and stop a database, see "Managing TimesTen Databases" in the Oracle TimesTen In-Memory Database Operations Guide.

There are two types of patch upgrades (or downgrades):

• Basic patch upgrade: A type of upgrade where the shared memory segment is destroyed when the database is stopped. A new shared memory segment is created when the database is started. This is the preferred method for performing a patch upgrade. See "About Performing a Basic Patch Upgrade" for details.

• Fast patch upgrade: A type of upgrade where the shared memory segment is preserved in memory when the database is stopped. The same memory segment is used when the database is started. This is the preferred method if your databases are large and you have both critical uptime requirements and short maintenance windows. See "About Performing a Fast Patch Upgrade" for details.