Replication of large objects

How Enterprise Replication handles simple and smart large objects depends on how the objects are stored.

Enterprise Replication replicates the following types of large objects:
  • Simple large object data types (TEXT and BYTE)

    You can store simple large objects either in the tblspace with the rest of the table columns (in a dbspace) or in a blobspace. Simple large objects in tblspaces are logged in the logical log and therefore, Enterprise Replication can evaluate the data for replication directly.

  • Smart large object data types (BLOB and CLOB)

    You must store smart large objects in sbspaces. Enterprise Replication cannot evaluate large object data that is stored in a blobspace or sbspace; instead, Enterprise Replication uses information about the large object that is stored in the row to evaluate whether the objects need to be replicated.

By default, Enterprise Replication does not include columns that contain unchanged large objects in replicated rows.

Enterprise Replication allows cross-replication between simple large objects and smart large objects. For example, you can replicate a simple large object on the source database server to a smart large object on the target server or vice versa.

If Enterprise Replication processes a row and discovers undeliverable large object columns, the following actions can occur:
  • Any undeliverable columns are set to NULL if the replication operation is an INSERT and the row does not already exist at the target.
  • The old value of the local row is retained if the replication operation is an UPDATE or if the row already exists on the target.