Adaptive Server provides SQL standard-compliant “chained” transaction behavior as an option. In chained mode, all data retrieval and modification commands (delete, insert, open, fetch, select, and update) implicitly begin a transaction. Since such behavior is incompatible with many Transact-SQL applications, Transact-SQL style (or “unchained”) transactions remain the default.
You can initiate chained transaction mode using the set chained option. The set transaction isolation level option controls transaction isolation levels. See Chapter 23, “Transactions: Maintaining Data Consistency and Recovery.”
