For an HDR database server pair to function, you must meet the following database and data requirements:
All databases that you want to replicate must have transaction logging turned on.
This requirement is important because the secondary database server uses logical-log records from the primary database server to update the data that it manages. If databases managed by the primary database server do not use logging, updates to those databases do not generate log records, so the secondary database server has no means of updating the replicated data. Logging can be buffered or unbuffered.
If you need to turn on transaction logging before you start HDR, see Turning On Transaction Logging with ontape.
If your primary database server has simple large objects stored in blobspaces, modifications to the data within those blobspaces is not replicated as part of normal HDR processing. However, simple-large-object data within dbspaces is replicated.
Smart large objects, which are stored in sbspaces, are replicated. The sbspaces must be logged. User-defined types (UDTs) are replicated, unless they have out-of-row data stored in operating system files. Data types with out-of-row data are replicated if the data is stored in an sbspace or in a different table on the same database server.