Patent attributes
A first column of a first database table may be transferred to a second table in a combined truncate and append operation in a transaction that may be atomic and reversible. References data for the first column may be removed from the first table and added to the second table. The combined operation may be reversed by removing, from the second table, references to blocks of data added to the second table prior to commencing the combined operation. A second column corresponding on a row-by-row basis to the first column may be added to the second table, where the data is indicative of visibility of data in the first column to other transactions on the second table.