Abstract: A method, article of manufacture, and apparatus for processing queries, comprising receiving a query, determining a query classification for the query, assigning the query to a resource queue based on the determined query classification, and placing the query in the assigned resource queue. In some embodiments, the resource queue is divided into a plurality of slots, and the query is placed in a slot. The resource queue may be associated with a resource queue memory allocation, and each of the plurality of slots is associated with a slot memory allocation.

Abstract: A method, article of manufacture, and apparatus for processing queries, comprising analyzing a query tree, determining at least one operator based on the query tree analysis, assigning a memory allocation for each of the at least one operator, and storing the assignment in a storage device. In some embodiments, a memory classification for each of the at least one operator is determined. In some embodiments, assigning a memory allocation for each of the at least one operator includes assigning a memory allocation based on the memory classification.

Abstract: A computer readable storage medium includes executable instructions to evaluate an expanded shared-nothing data store configuration. A data redistribution schedule table with specified parameters is formed. Data is redistributed within the expanded shared-nothing data store in accordance with the data redistribution schedule table.

Abstract: A method of analyzing the performance of a query optimizer includes identifying an event trigger. A reproduction object characterizing operational parameters of the customer computer at the time of the event trigger is populated. The reproduction object is transported from the customer computer to a test computer. The reproduction object is analyzed at the test computer to characterize the performance of a query optimizer.

Abstract: A computer readable storage medium comprises executable instructions to receive a query. A graph is built to represent jobs associated with the query. The jobs are assigned to parallel threads according to the graph.

Abstract: SQL queries are optimized to operate directly on compressed data (and obtain the correct result) rather than requiring that the data be first decompressed prior to processing a query. Certain characteristic pattern trees are mapped against a logical input query plan that includes certain logical operators such as a DECOMPRESS that precedes a JOIN or a GROUPBY in association with a COUNT to identify instances in the plan that match a characteristic pattern. Upon locating a match, the input query plan is transformed into a logically equivalent plan that operates correctly on compressed data, by analyzing the interplay of the semantics of logical query operations with the compressed data and substituting less costly structures and operations. DECOMPRESS operations are moved to operate subsequent to a JOIN or eliminated altogether, and COUNT operations are replaced by a different operation, such as SUM, that is logically equivalent for compressed data.

Abstract: A method, article of manufacture, and apparatus for processing queries, comprising performing a query with a first memory intensive allocation, receiving an indication that a memory intensive operator spilled to a first storage device, adjusting a resource queue memory allocation based on the indication, computing a second memory intensive allocation based on the adjusted resource queue memory allocation, and storing the second memory intensive allocation in a second storage device.

Abstract: A scalable job scheduler for a multi-thread, multi-processor system synchronizes and schedules jobs for execution by using lists and jobs counters for the numbers of active jobs. It minimizes synchronization overhead by using atomic operations for incrementing and decrementing the counters. The scheduler assigns jobs for execution, and can awake up an available thread to pick up work. A parent job spawns child jobs and maintains a job counter. Spawned jobs are added to the list for execution and the counter of waiting jobs is incremented. When execution of a job begins, the parent's counter of outstanding child jobs is decremented. A parent job is suspended until its counter of uncompleted spawned child jobs reaches zero. As a job is completed, the scheduler decrements the counter of active jobs, and assigns the next job in the queue to an available thread.

Abstract: A method of analyzing the performance of a query optimizer includes identifying an event trigger. A reproduction object characterizing operational parameters of the customer computer at the time of the event trigger is populated. The reproduction object is transported from the customer computer to a test computer. The reproduction object is analyzed at the test computer to characterize the performance of a query optimizer.

Abstract: A computer readable storage medium includes executable instructions to evaluate an expanded shared-nothing data store configuration. A data redistribution schedule table with specified parameters is formed. Data is redistributed within the expanded shared-nothing data store in accordance with the data redistribution schedule table.

Abstract: The invention enables a correlated or multi-row subquery (CSQ) to be performed on distributed MPP and shared-nothing databases by broadcasting intermediate results, prior to a correlation operation, from subquery execution on one segment to all other segments in the distributed database so that the respective CSQs of each segment will have access to the necessary results to permit correct execution of the CSQ. Additionally, the intermediate results are saved to disk to avoid the necessity of replicating the same intermediate results multiple times during execution of a subquery plan.

Abstract: A computer readable storage medium includes executable instructions to evaluate an expanded shared-nothing data store configuration. A data redistribution schedule table with specified parameters is formed. Data is redistributed within the expanded shared-nothing data store in accordance with the data redistribution schedule table.

Abstract: Server supervisor processes in the segment nodes of a database cluster afford transparent reset mechanisms to a fault tolerant service (FTS). FTS probes only primary segments as to their status unless a primary segment does not respond, in which case FTS will probe the mirror of that primary-mirror pair, and change the state of the mirror to primary if the primary is faulty. Only a primary segment to initiate a reset of its mirror segment and then resets itself. If a mirror segment fails, it shuts down and its corresponding primary segment will report the failure to FTS. Transient communication failures are addressed by retry logic on FTS probing, and not reported to FTS. Reset is not initiated by FTS and preserves the segment state in the absence of errors.

Abstract: A shared nothing distributed database system includes a master node and a set of shared nothing nodes. Each shared nothing node includes a node state table stored in memory that characterizes various statements and multiple processes implementing each statement, target resource consumption rate for each process and process activity information. A monitor module executed by a central processing unit processes information in the node state table and adjusts values in the node state table in accordance with priority criteria specifying individual user priority ascribed to a statement. A query associated with a statement is processed in the shared nothing distributed database system in accordance with the priority criteria.

Abstract: A method, article of manufacture, and apparatus for processing queries, comprising analyzing a query tree, determining at least one operator based on the query tree analysis, assigning a memory allocation for each of the at least one operator, and storing the assignment in a storage device. In some embodiments, a memory classification for each of the at least one operator is determined. In some embodiments, assigning a memory allocation for each of the at least one operator includes assigning a memory allocation based on the memory classification.

Abstract: A method, article of manufacture, and apparatus for processing information are disclosed. In some embodiments, this includes receiving a query plan, generating a work file based on the query plan, associating the query plan with a work file, storing the association, and storing the work file in a storage device after the query plan has executed. In some embodiments, a hash of the query plan may be generated.

Abstract: A computer readable storage medium includes executable instructions to evaluate an expanded shared-nothing data store configuration. A data redistribution schedule table with specified parameters is formed. Data is redistributed within the expanded shared-nothing data store in accordance with the data redistribution schedule table.

Abstract: A shared nothing distributed database system includes a master node and a set of shared nothing nodes. Each shared nothing node includes a node state table stored in memory that characterizes various statements and multiple processes implementing each statement, target resource consumption rate for each process and process activity information. A monitor module executed by a central processing unit processes information in the node state table and adjusts values in the node state table in accordance with priority criteria specifying individual user priority ascribed to a statement. A query associated with a statement is processed in the shared nothing distributed database system in accordance with the priority criteria.

Abstract: A computer readable storage medium comprises executable instructions to receive a query. A graph is built to represent jobs associated with the query. The jobs are assigned to parallel threads according to the graph.