Upgrades When Using Parallel Replication

You can perform an online or offline upgrade from a database that has not enabled parallel replication to a database that has enabled automatic parallel replication (with or without disabled commit dependencies). See ReplicationApplyOrdering attribute, in the Oracle TimesTen In-Memory Database Reference for information on setting automatic parallel replication values.

The remainder of this section discusses additional considerations along with scenarios where an offline upgrade is required.

Considerations Regarding Parallel Replication

Be aware of the following considerations when upgrading hosts that use parallel replication:

Consider an active standby pair without parallel replication enabled. To upgrade the instances to a 22.1 release and use automatic parallel replication (default value of 0 for the ReplicationApplyOrdering attribute), use the appropriate procedure for an active standby pair upgrade. See Performing an Upgrade with Active Standby Pair Replication for details.
Consider an active standby pair with no cache groups and automatic parallel replication enabled (value of 0 for the ReplicationApplyOrdering attribute). To upgrade the instances to a 22.1 release to use automatic parallel replication with disabled commit dependencies (value of 2 for the ReplicationApplyOrdering attribute), use the procedure for an active standby pair online major upgrade. See Online Major Upgrade for Active Standby Pair for details. The value for the ReplicationApplyOrdering attribute must be changed from 0 to 2 before restoring any of the databases. For example:
```
ttMigrate -r "DSN=master2;ReplicationApplyOrdering=2;ReplicationParallelism=2;
  LogBufParallelism=4" master2.bak
```
Note:

You may upgrade a database with a replication scheme with ReplicationApplyOrdering=2 to a database with ReplicationApplyOrdering=0 by using the same active standby pair online major upgrade procedure.

Automatic parallel replication with disabled commit dependencies supports only asynchronous active standby pairs with no cache groups. For more information, see Configuring Parallel Replication in the Oracle TimesTen In-Memory Database Replication Guide.
You cannot replicate between databases that have the ReplicationParallelism attribute set to greater than 1 but have different values for the ReplicationApplyOrdering attribute.

Scenarios That Require an Offline Upgrade

You must use an offline upgrade for these scenarios:

Moving from an automatic parallel replication environment to another automatic parallel replication environment with a different number of tracks, as indicated by the value of the ReplicationParallelism attribute.
Moving between major releases (for example, from 18.1 to 22.1) and using asynchronous writethrough cache groups.
Moving from regular replication with asynchronous writethrough in 18.1 to automatic parallel replication with asynchronous writethrough in 22.1.

Use the procedure described in "Moving to a Different Major Release Using ttMigrate" for offline upgrades. Alternatively, you can upgrade one side and use the ttRepAdmin -duplicate -recreate command to create the new database.