Log Records

What
A log record is stored in the database and has information about an action so that it can be redone or undone later on if the system crashes or a transaction needs to abort.

Attributes
For update records only:
 * LSN
 * PrevLSN
 * XID
 * type - {Update, Commit, Abort, Checkpoint, End}
 * PageID
 * length
 * offset
 * before-image
 * after-image