In OpenEdge Releases prior to 10.1A, ABL allowed large object (BLOB and CLOB) operations in subtransactions. However, if the user undid the subtransaction they got the following message:

Undo of sub-transaction modifying a large object.  Backing out transaction. 
(11599)

This message told the user that not just the subtransaction, but the entire transaction was rolled back.

Starting with Release 10.1A, subtransactions containing changes to large object (LOB) fields can be undone without undoing the entire transaction. Users no longer get the previous message and, more importantly, the subtransaction containing the LOB operation is rolled back like any other subtransaction. This feature applies only to LOB operations in the OpenEdge database.

The OpenEdge DataServers support savepoint-based UNDO of subtransactions with LOBs. The following table lists the supported releases and reference topics:
DataServer Supported from For more information...
Microsoft SQL Server OpenEdge Release 11.7.2

See Handling rollback of sub-transactions in Use Microsoft SQL Server DataServer
Oracle OpenEdge Release 12.3

See Handling rollback of sub-transactions in Use the Oracle Data Server

Note that this feature does not apply to temporary tables. Temp-tables must be NO-UNDO if they contain binary (BLOB) or character large object (CLOB) fields.