Abstract:
Computer-implemented methods, modules and clients relate to expanded, pruned sample table for testing database queries against a base table. The expanded, pruned sample table is formed from the base table by a process of initial sampling, synthesis, and pruning.
Abstract:
A technique is described that reduces the complexity and resource consumption associated with performing record expiry in a distributed database system. In accordance with the technique, a record is checked to see if it has expired only when it has been accessed for a read or a write. If at the time of a read a record is determined to have expired, then it is not served. If at the time of a write a record is determined to have expired, then the write is treated as an insertion of a new record, and steps are taken to treat the insertion consistently with regard to the previous expired version. A background process is used to delete records that have not been written to or actively deleted by a client after expiration.
Abstract:
A novel method is employed for collecting optimizer statistics for optimizing database queries by gathering feedback from the query execution engine about the observed cardinality of predicates and constructing and maintaining multidimensional histograms. This makes use of the correlation between data columns without employing an inefficient data scan. The maximum entropy principle is used to approximate the true data distribution by a histogram distribution that is as “simple” as possible while being consistent with the observed predicate cardinalities. Changes in the underlying data are readily adapted to, automatically detecting and eliminating inconsistent feedback information in an efficient manner. The size of the histogram is controlled by retaining only the most “important” feedback.
Abstract:
A system and method for deriving user intent from a query. The system includes a query engine, and an advertisement engine. The query engine receives a query from the user. The query engine analyzes the query to determine a query intent that is matched to a domain. The query may be further analyzed to derive predicate values based on the query and the domain hierarchy. The domain and associated information may then be matched to a list of advertisements. The advertisement may be assigned an ad match score based on a correlation between the query information and various listing information provided in the advertisement.
Abstract:
A novel method is employed for collecting optimizer statistics for optimizing database queries by gathering feedback from the query execution engine about the observed cardinality of predicates and constructing and maintaining multidimensional histograms. This makes use of the correlation between data columns without employing an inefficient data scan. The maximum entropy principle is used to approximate the true data distribution by a histogram distribution that is as “simple” as possible while being consistent with the observed predicate cardinalities. Changes in the underlying data are readily adapted to, automatically detecting and eliminating inconsistent feedback information in an efficient manner. The size of the histogram is controlled by retaining only the most “important” feedback.
Abstract:
A method, an apparatus, a computer-program product, and a system for determining bandwidth for transmission of data packets are disclosed. A data packet in a plurality of data packets is received. An amount of bandwidth required for transmission of the received data packet is determined. The amount of bandwidth is a portion of a total available bandwidth for a radio link. At least one condition associated with the radio link for transmitting the received data packet to a user device is determined. Based on the determined amount of bandwidth and the determined condition, the received data packet is transmitted to the user device. Another data packet in the plurality of data packets is transmitted using another portion of the total available bandwidth.
Abstract:
A real-time messaging platform and method is disclosed which classifies messages in accordance with a combination of user engagement events as modified to reflect the temporal structure of the user engagement events. A message can be assigned a metric based, for example, on a weighted combination of user engagement rates, decayed with time to reflect an intuition that recent interactions by one or more users with the message will have a greater impact than older interactions with the message. Different types of interaction by one or more users with the message can be assigned different weights when the different engagement events are combined and, also, can be assigned different temporal characteristics.
Abstract:
Techniques that support trail-based exploration by a user of a repository of documents are described herein. In one embodiment, trail definition data that specifies a trail is received. The trail includes an ordered series of waypoints including a trailhead, intermediate waypoints, and one or more trailends. In some embodiments, deadends may also be defined in the trial. A particular waypoint in the ordered series of waypoints is established as a current waypoint. Search terms can be received from a user to cause a search to be performed. It is then determined whether the search satisfies matching criteria associated with a waypoint that immediately follows the current waypoint in the ordered series of waypoints. If so, the user advances to the next waypoint. Otherwise, the user remains at the current waypoint. Finally, if a trailend is reached, then an action such as rewarding the user in some way may be performed.
Abstract:
A technique is described that reduces the complexity and resource consumption associated with performing record expiry in a distributed database system. In accordance with the technique, a record is checked to see if it has expired only when it has been accessed for a read or a write. If at the time of a read a record is determined to have expired, then it is not served. If at the time of a write a record is determined to have expired, then the write is treated as an insertion of a new record, and steps are taken to treat the insertion consistently with regard to the previous expired version. A background process is used to delete records that have not been written to or actively deleted by a client after expiration.
Abstract:
A system is described for providing scalable in-memory caching for a distributed database. The system may include a cache, an interface, a non-volatile memory and a processor. The cache may store a cached copy of data items stored in the non-volatile memory. The interface may communicate with devices and a replication server. The non-volatile memory may store the data items. The processor may receive an update to a data item from a device to be applied to the non-volatile memory. The processor may apply the update to the cache. The processor may generate an acknowledgement indicating that the update was applied to the non-volatile memory and may communicate the acknowledgment to the device. The processor may then communicate the update to a replication server. The processor may apply the update to the non-volatile memory upon receiving an indication that the update was stored by the replication server.