Map data consistency

In this section, learn how to manage data in the catalog version:

• Update data in a catalog verison
• Remove data from a catalog version
• Switch to a new catalog version

Update data in a catalog version

To update data to a new catalog version:

1. Create a new DataStoreClient instance pointing to a new catalog version.
2. Drop the DataStoreClient instance pointing to the old catalog version.
3. Clear the relevant cache on your side containing the decoder tile data from the old catalog version.

Notes:

• Do not reuse old tile data with new catalog version data.

• If data has not changed between the old and new catalog versions, do not handle it by yourself as only OCMAM is aware of it. In this case, OCMAM manages the data on its side.

• To consume data from a particular catalog version, use separate DataStoreClient instances for each catalog version. We do not recommended mixing OCM data from different DataStoreClient instances.

• We recommended managing the mutable and protected cache separately. To manage cache separately, create individual DataStoreClient instances for each of the mutable and protected cache.

Evict data from a catalog version

If you no longer need data from a catalog version, you can evict it from the DataStoreServer instance.

To evict data from the catalog version:

1. Destroy all the DataStoreClient instances using the catalog version.

2. Release the catalog from the DataStoreServer instance using its catalog handle:

   server->ReleaseCatalog( catalog_handle );
   

Switch to a new catalog version

Before switching to a new catalog version, perform the following actions:

1. Create the DataStoreClient instance for the new catalog version.
2. Prefertch all the needed data for the new catalog version.
3. Switch to the new catalog version after the data is prefetched.
4. After you switch to the new catalog version, drop the DataStoreClient instance pointing to the old catalog version.

Notes:

• To switch to a newer or older catalog version, destroy all the DataStoreClientinstances. When all DataStoreClient instances are destroyed, DataStoreServer removes the particular version from the instance automatically.

• The catalog version remains in the DataStoreServer for as long as at least one DataStoreClient instance points to the catalog.