Sparse indexing has been around for a number of versions. The history of these on the z/Os side goes back to originally helping with non-correlated subqueries in V4, then star joins in V7, to hashing support of these indexes in V10.
Business data is usually stored in relational databases, where it persists for use by enterprise applications. Applications use SQL, typically embedded within a programming language, to store and retrieve the data.
Today data exists everywhere. You can find it in databases and big data clusters, in branch offices or manufacturing devices, in ATMs, in cars, trucks, and in sensors. The typical enterprise may have hundreds of different data sources containing the valuable data you need.