Patent ID: 7774565

Claim:
A method to access data from a previous point in time, comprising: providing a journal history of write transactions comprising: a DO stream comprising data for writing in a storage system; an UNDO stream comprising data that is overwritten in the storage system; a DO metadata stream comprising a first pointer to an offset in the DO stream where the data for writing in a storage system is located; an UNDO metadata stream comprising a second pointer to an offset in the UNDO stream where the data that is overwritten is located; writing new data to the storage system if the data that is to be overwritten is transferred to the UNDO stream; receiving data stored in the storage system of addressable memory, the storage system including a plurality of addresses; receiving the journal history of write transactions for the storage system, each write transaction comprising a plurality of designated memory addresses, a corresponding plurality of current data to write in the designated memory addresses for storage, and a time indicator; rolling back to data that was stored at a specified point in time by copying data from the UNDO stream to the storage system to form a rolled back storage; generating a data structure that represents a virtual interface to the rolled back storage at the specified point in time based on the write transactions in the journal history having a time subsequent to the specified point in time; and enabling a user to process data from the specified point in time, via the virtual interface and the journal history.