US Patent 7305386 Controlling visibility in multi-version database systems

A multi-version database system controls visibility of data during transaction processing. A transaction includes a transaction identifier that identifies the transaction and an invisibility list of transactions whose effects are invisible to the transaction. Changes made by other transactions are visible to the transaction based on the isolation level of the transaction. Records are visible to a transaction based on a creator identifier stored in the record that identifies the transaction that created the record.