Abstract: An aspect of the invention relates to a method for centrally updating inventory of electronic provider objects comprising: merging a plurality of object changes from a first queue by change category; for each change category, determining an impact of the merged object changes on a set of data pairs in a general database, each data pair being formed by two given attributes of an electronic provider object placing each impacted data pair in a second queue; determining, for each impacted data pair, an update of the two given attributes of an electronic provider object over a second predetermined period via a query to the general database.

Abstract: A database system, method, and computer program product of handling purchases of products is presented, in which the database system comprises a relational database storing relational data for a plurality of products, a key-value database storing a plurality of first files and a plurality of second files, an interface module connecting the relational database with the key-value database, and a shopping engine to communicate with the key-value database. The interface module converts relational data stored in the relational database into first files and second files. The shopping engine queries the key-value database to retrieve available products in response to an availability request.