Computing the Cost of Compressed Data

Synonyms

Data archiving; Data compression; Data retention

Definitions

Compression mechanisms reduce the storage cost of retained data. In the extreme case of data that must be retained indefinitely, the initial cost of performing the compression transformation can be amortized down to zero, since the savings in storage space continue to accrue without limit, albeit at decreasing rates as time goes by and disk storage becomes cheaper. A more typical scenario arises when a fixed data retention period must be supported, after which the stored data is no longer required; and when a certain level of access operations to the stored data can be expected, as part of a regulatory or compliance environment. In this second scenario, the total cost of retention(TCR) is a function of multiple competing factors, and the compression regime that provides the most compact storage might not be the one that provides the smallest TCR. This entry summarizes recent work in the area of cost models for data...