The Teradata Database configuration determines how to archive when AMPs are offline. If a table has fallback protection or dual after-image journaling, Teradata ARC makes a complete copy of the data rows, even if an AMP (per cluster) is offline during the archive. For a cluster archive, only AMPs within specified clusters are considered.
All Teradata Database dictionary rows are defined with fallback. Therefore, Teradata ARC always performs a complete archive of the necessary dictionary entries, even if AMPs are offline. This is also true when database DBC is archived.
Consider a situation where:
- AMPs are offline
- A request is made for an all-AMPs or a cluster archive involving one of the following:
- Nonfallback tables
- Journal table archive that contains single images
In this situation, a specific AMP archive for the offline processors after the AMPs are back online is required.
Single after-images (remote or local) are maintained on single AMPs, therefore after-images for offline AMPs are not included in the archive. If one of these archives is restored with a rollforward operation, data from some of the online AMPs is not rolled forward.