Abstract: Disclosed herein are system, method, and computer program product embodiments for generating join histograms. An embodiment operates by a computer implemented method that includes determining, by at least one processor, a first interval associated with a first histogram of a first data structure and a first estimate frequency associated with the first interval. The method further includes determining, by the at least one processor, a second interval associated with a second histogram of a second data structure and a second estimate frequency associated with the second interval. The method further includes determining, by the at least one processor, a join interval based on the first and second intervals by calculating an intersection of the first and second intervals. The method further includes calculating, by the at least one processor, a join estimate frequency based on the first and second estimate frequencies.

Abstract: Systems, methods and computer program product embodiments for providing table parameterized function (TPF) functionality in a database are disclosed herein. An embodiment includes defining a TPF in a database, wherein the definition of the TPF defines one or more parameters of the TPF, at least one of the parameters being a table parameter. A query is received that operates to call the TPF, wherein the query defines one or more input parameters, the input parameters comprising at least one table input parameter to be used as input for calling the TPF. The query is processed to produce a result, and the result of the query is returned.

Abstract: A system, computer-implemented method, and computer-program product embodiments for determining a cardinality estimate for a query. A cardinality estimator identifies a predicate in a query, where the predicate is split into a plurality of equivalence classes. The cardinality estimator then generates a plurality of equivalence graphs from the plurality of equivalence classes, one equivalence graph for an equivalence class. Spanning trees are identified from the plurality of equivalence graphs, and the cardinality estimator then determines the cardinality estimate for the query from the spanning trees.

Abstract: Cracking page-loadable columns for in-memory data management is described herein. An embodiment operates by accessing a column according to a received query, determining that the received query requires a non-critical data structure associated with the column, and rebuilding the non-critical data structure from data associated with the column.

Abstract: A system includes determination of a plurality of secondary data structures of a database to be rebuilt, determination, for each of the plurality of secondary data structures, of a current ranking based on a pre-crash workload, a crash-time workload, the post-crash workload, and a rebuild time of the secondary data structure, determination to rebuild one of the plurality of secondary data structures based on the determined rankings, and rebuilding of the one of the plurality of secondary data structures in a dynamic random access memory based on primary data of a database stored in non-volatile random access memory.

Abstract: The present disclosure involves systems, software, and computer implemented methods for providing quality-driven processing of out-of-order data streams based on a configurable quality metric. In one example, the method includes identifying a configurable quality metric defined by a user or application for executing continuous queries over a sliding window, the metric specifying a user requirement for the quality of the continuous query result. A quality threshold metric is calculated based on the configurable quality metric, the configurable quality metric associated with a size of an adaptation buffer for incoming tuples of the query. In response to receiving a signal indicating a new query result, a sliding window prior to a current time is identified. A runtime quality metric associated with the incoming tuples for the sliding window is measured, and the adaptation buffer is modified based on a difference between the quality threshold metric and the measured runtime quality metric.

Abstract: The present disclosure involves systems, software, and computer implemented methods for optimizing continuous queries for hybrid execution over a stream processing engine and an in-memory database. In one example, a method may include identifying a continuous query executed at a stream processing engine, the continuous query including a plurality of operators. An optimal plan for execution of the identified continuous query at the stream processing engine is determined. For each of the plurality of operators in the determined optimal plan, an optimized placement decision for executing a particular operator in the stream processing engine or at a database system is determined. An optimized continuous query is generated from the identified continuous query based on the determined optimal placement decisions for each of the plurality of operators in the determined optimal plan. The optimized continuous query is then executed at the stream processing engine and the database system.

Abstract: Disclosed herein are system, method, and computer program product embodiments for accessing and managing storage class memory (SCM) enabled main-memory database structures. An embodiment operates by traversing a first node to find a location of a second node corresponding to a search key, calculating a hash value for the search key, comparing the calculated hash value with at least one fingerprint value stored in the second node, wherein the fingerprint value is determined by hashing a stored key, accessing at least one key-value pair having a matching hash value, and returning a value associated with the matching key-value pair, wherein at least one of the traversing, calculating, comparing, accessing, and returning are performed by one or more computers.

Abstract: A method and system, the system including a plurality of machines each having a processor and a main memory component; a shared distributed storage facility storing a set of data and accessible by the plurality of machines over a communication network; a controller to select, in response to a state of a query execution plan comprising a plurality of executable jobs for the set of data, which one of a set of scheduling algorithms to execute; an execution engine to execute the selected scheduling algorithm to determine, for each job in the plurality of jobs, which server to schedule to execute the respective job; and providing an indication of the scheduling of the servers determined to be schedules for the execution of the jobs.

Abstract: The invention relates to a computer system and a corresponding method and a corresponding computer-readable medium. The computer system is suitable for determining the result of a join. Based on the access pattern of an application, the computer system infers that a particular subjoin is empty. The computer system then excludes the inferred-empty subjoin when performing the join, performing a more efficient and faster database join operation.

Abstract: A system includes determination of a plurality of secondary data structures of a database to be rebuilt, determination, for each of the plurality of secondary data structures, of a current ranking based on a pre-crash workload, a crash-time workload, the post-crash workload, and a rebuild time of the secondary data structure, determination to rebuild one of the plurality of secondary data structures based on the determined rankings, and rebuilding of the one of the plurality of secondary data structures in a dynamic random access memory based on primary data of a database stored in non-volatile random access memory.

Abstract: In an optimizer within a Relational Database Management System improved ways in which a search space (the universe of possible join combinations) is generated and managed and improved ways in which the elements of a search space are evaluated so that among other things unpromising elements are efficiently dropped (pruned).

Abstract: Disclosed herein are system, method, and computer program product embodiments for performing resource estimation for query optimization. An embodiment operates by generating a subplan for which an optimization process may be invoked, predicting performance and resource consumption for optimizing the subplan by measuring similarity between a hypergraph of the subplan and one or more etalon queries having known performance and resource consumption properties, selecting an algorithm for optimizing the subplan from a plurality of optimization algorithms based on the performance and resource consumption properties, and generating an optimized access plan using the selected algorithm.

Abstract: A system, computer-implemented method, and computer-program product embodiments for generating a multi-dimensional histogram. A data statistic object generator creates an initial histogram, determines a cost associated with each bucket of the histogram, sorts the buckets into a queue based on the determined cost and selects one of the buckets to be decomposed based on the determined cost. The cost of the decomposed buckets are then calculated, and the decomposed are buckets are then put back into the queue of histogram buckets for possible further decomposition.

Abstract: A system, computer-implemented method, and a computer-readable storage medium for determining estimations to statistical questions. Data statistics used in evaluating estimations to statistical questions are gathered from multiple sources in a database management system. A statistical question comprising, for example, cardinality estimations is received, wherein the question is posed by different database components, such as query optimizer, or execution engine. Estimation for the statistical question is computed, where the estimation is based on multiple data statistics and without using the data referred to in the question.

Abstract: The invention relates to a computer system and a corresponding method and a corresponding computer-readable medium according to the invention. The computer system is suitable for determining the result of a join. The computer system may be distributed system.

Abstract: Disclosed herein are system, method, and computer program product embodiments for performing resource estimation for query optimization. An embodiment operates by generating a subplan for which an optimization process may be invoked, predicting performance and resource consumption for optimizing the subplan by measuring similarity between a hypergraph of the subplan and one or more etalon queries having known performance and resource consumption properties, selecting an algorithm for optimizing the subplan from a plurality of optimization algorithms based on the performance and resource consumption properties, and generating an optimized access plan using the selected algorithm.

Abstract: A system, computer-implemented method, and computer-program product embodiments for generating an access plan. A query optimizer includes an enumeration method which enumerates a plurality of subsets of a query. Each subset in the query has a plurality of partitions. The partitions of each subset are enumerated into enumerated partitions using at least one thread. For each partition, physical access plans are generated, using at least one thread. Physical access plans are generated in parallel with other physical access plans of different partitions and with other enumerating partitions. The number of threads that perform the enumeration and the generation is dynamically adapted according to a pool of threads available during the enumeration of the partitions and the generation of physical access plans, and a complexity of the query. From the generated physical access plans, a final access plan for the query is determined by choosing the most efficient access plan.

Abstract: Systems, methods and computer program product embodiments for providing table parameterized function (TPF) functionality in a database are disclosed herein. An embodiment includes defining a TPF in a database, wherein the definition of the TPF defines one or more parameters of the TPF, at least one of the parameters being a table parameter. A query is received that operates to call the TPF, wherein the query defines one or more input parameters, the input parameters comprising at least one table input parameter to be used as input for calling the TPF. The query is processed to produce a result, and the result of the query is returned.

Abstract: Systems, methods and articles of manufacture for determining at least one algorithm from a pool of algorithms to optimize a query. An embodiment includes building optimization blocks for the subplan, determining the complexity of the subplan based on the optimization blocks and selecting an algorithm from a pool of search space generation algorithms based on complexity of the subplan and characteristics of the selected algorithm, and optimizing the subplan with the selected algorithm.