1. In a computer system, a method for correlating information from one or more sources, comprising: receiving, at a key authority, notification of a change to an attribute of an entity, the entity prior to the change being associated with a first surrogate key; deferring the use of a second surrogate key, generated in response to the change, until a selected time, wherein the second surrogate key was generated to reflect the change; receiving from a first source system an event notification, the event notification comprising event information and a source specific key; determining a third surrogate key corresponding to the source specific key; determining a hint associated with at least one of the first and second surrogate keys; mapping the hint and third surrogate key to determine the first surrogate key; and using the first surrogate key in a row of a table.