Abstract: A database server is communicatively coupled to a database storing multiple data records which are accessible by a number of data access systems communicatively coupled to the database server in order to claim exclusive access to a data record for a specifiable time period by one of the data access systems. The database server stores associations of the data records with the data access systems defining which data access system is generally allowed to access to which data record and an exclusive access times inventory defining which of the data access systems with allowed access has already been granted exclusive access to which data record for which time periods.

Abstract: A database server is communicatively coupled to a database storing multiple data records which are accessible by a number of data access systems communicatively coupled to the database server in order to claim exclusive access to a data record for a specifiable time period by one of the data access systems. The database server stores associations of the data records with the data access systems defining which data access system is generally allowed to access to which data record and an exclusive access times inventory defining which of the data access systems with allowed access has already been granted exclusive access to which data record for which time periods.

Abstract: A computer-implemented method comprising: receiving a user-generated request comprising functional data; retrieving a list of data items and a set of dependency rules, each data item being assigned an undefined binary validity value; generating a directed graph by organizing the data items in accordance with the retrieved dependency rules; applying a filtration process to solve the directed graph comprising: calculating the validity value; propagating the validity values through the graph; and filtering the directed graph by keeping only nodes having a validity value of one; calculating, for each filtered data item, a price; and generating a list of available data items with their price. The node suppression decreases the number of data items for which a price has to be calculated, thereby saving resources and/or decreasing the time needed to resolve the user request.