Patent ID: 7865962

Claim:
A system, comprising: at least one object, the at least one object being associated with data; a multi-level sequence number associated with the data for the at least one object, the multi-level sequence number comprising a first portion uniquely identifying a data provider, the data provider supplying the data associated with the at least one object, and a second portion common to a plurality of data providers; a cache containing a cached value of the multi-level sequence number and a cached value of the data; and a global table comprising a current value of the multi-level sequence number, wherein: when the data for the at least one object is requested, a comparison is performed of the cached value of the multi-level sequence number with the current value of the multi-level sequence number, the comparison comprising: comparing the first portion of the cached value of the multi-level sequence number with the first portion of the current value of the multi-level sequence number; and when the first portion of the cached value of the multi-level sequence number matches the first portion of the current value of the multi-level sequence number, comparing the second portion of the cached value of the multi-level sequence number with the second portion of the current value of the multi-level sequence number; and when the data associated with the at least one object changes, the current value of the multi-level sequence number in the global table is updated, the updating comprising: incrementing the value of the first portion of the current value of the multi-level sequence number in the global table; and when incrementing the value of the first portion of the current value of the multi-level sequence number causes the value of the first portion of the current value of the multi-level sequence number to reduce to an initial value, then incrementing the value of the second portion of the current value of the multi-level sequence number in the global table.