Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for controlling access to APIs. One of the methods includes receiving a request from a client for a computer authorization challenge to access an application programming interface; determining a computer authorization challenge with a difficulty of completion that satisfies a target computational cost for the application programming interface; and providing the computer authorization challenge to the client for access to the application programming interface.

Abstract: Automatically extracting profile feature attribute data from event data is disclosed, including: receiving a set of event data; receiving a feature associated with a profiling technique; determining that a plurality of events associated with a user in the set of event data corresponds to a first attribute corresponding to the feature, wherein the first attribute corresponds to a first bin having a first defined value; determining that the plurality of events associated with the user in the set of event data corresponds to a second attribute corresponding to the feature, wherein the second attribute corresponds to a second bin having a second defined value; and creating a user record corresponding to the user indicating presence in the first bin and the second bin.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for controlling access to APIs. One of the methods includes receiving a request from a client for a computer authorization challenge to access an application programming interface; determining a computer authorization challenge with a difficulty of completion that satisfies a target computational cost for the application programming interface; and providing the computer authorization challenge to the client for access to the application programming interface.

Abstract: A task schedule is enforced among multiple processes by setting process priorities based upon which tasks are running on which processes and based upon the task schedule. The task scheduling may be provided by a local or global scheduler which uses application information to prioritize tasks. The task schedule, or priority list, is provided at Local Activity Schedulers which schedule the activities for their local execution elements/nodes. Execution of activities locally are performed by any number of processes that reside in each execution element. These processes are assigned operating system priorities by the respective Local Activity Scheduler based on their assigned activities for execution and the task schedule.

Abstract: An apparatus and method for approximating the data stored in a databases by generating multiple projections and representations from the database such that the OLAP queries for the original database (such as aggregation and histogram operations) may be applied to the approximated version of the database, which can be much smaller than the original databases. Other aspects optimize a mapping, via a mapping (or dimension) table, of non-numeric or numeric attributes to other numeric attributes such that the error incurred on applying queries to the approximated version of the database is minimized. Still further aspects define boundaries of approximations so that the boundaries are preserved when approximated versions of the databases are generated.

Abstract: A method and system for recovering from a failure of a processing node in a partitioned shared nothing database processing system are provided. The processing system may include a pair of processing nodes having twin-tailed-connected thereto a storage device. A first processing node of the pair of processing nodes has a first database instance running thereon which accesses a first data partition on the storage device prior to the failure. Upon detection of the failure, access to the first data partition on the storage device is provided to a third, spare processing node through the second processing node of the pair of processing nodes. The third processing node runs a replacement database instance for the first database instance which was running on the first processing node prior to the failure thereof. The replacement database instance accesses the first data partition on the storage device through the second processing node, thereby recovering from the failure of the first processing node.