Abstract: Techniques that facilitate management of skewed data during a parallel multiple join operation are provided. Portions of tables involved in the join operation can be distributed among a plurality of processing modules, and each of the processing modules can be provided with a list of skewed values of a join column of a larger table involved in the join operation. Each of the processing modules can scan the rows of first and second tables distributed to the processing modules and compare values of the join columns of both tables with the list of skewed values. One or more of the processing modules can then redistribute the skewed values.

Abstract: A request for at least a portion of a business object is received by a database from a client in a first half of a roundtrip between the client and the database. Each of the tables includes a primary key column and a plurality of records. The primary key column provides, for each record in the table, a primary key for one of a plurality of business objects. Thereafter, the database identifies records within a set of tables among a larger number of tables in the database by matching a primary key associated with the business object with the primary key in the primary key column. Once this identification has been made, the database obtains all values responsive to the request from the identified record and transmits, in a second half of the roundtrip between the client and the database, the obtained values for the business object to the client.

Abstract: Bloom filter cost estimation engine for improved performance and accuracy is described. An example method includes building an execution plan for a join operation having a plurality of levels, where the execution plan includes a top join operator at a top level, a leaf scan operator on a bottom level, and one or more intermediate operators between the top level and the bottom level. A row reduction effect of applying a Bloom filter is determined by simulating a semi-join operation over table statistic representation at each of the plurality of levels of the execution plan. A cost savings of the join operation is calculated based on the row reduction effect at the each of the plurality of the levels.

Abstract: For managing a database in a data-processing system, a polymorph table and a mapping structure are provided. The polymorph table includes a discrimination column and a total number of columns of each type equal to a maximum of the virtual columns of the type. The mapping structure stores information mapping each virtual column to a polymorph column of the same type. A virtual access request is received based on one of the virtual columns of one of the virtual tables. Selected mapping information is retrieved that maps each selected virtual column to one of the polymorph columns. The virtual access request is converted into a polymorph access request according to an identifier of the selected virtual table and the selected mapping information. The polymorph table is accessed according to the polymorph access request.

Abstract: A system and method of creating an access plan for a database query is disclosed. The system and method include identifying a first portion of a column of a table of a database. The first portion of the column may be in a select statement of the database query. The system and method include estimating a first statistical value for the column. The estimating may occur by analyzing a second portion of the column. The system and method include generating the access plan to predict a characteristic of a set of results for the database query. In generating the access plan, the first statistical value for the column may be used.

Abstract: Optimizing collective operations including receiving an instruction to perform a collective operation type; selecting an optimized collective operation for the collective operation type; performing the selected optimized collective operation; determining whether a resource needed by the one or more nodes to perform the collective operation is not available; if a resource needed by the one or more nodes to perform the collective operation is not available: notifying the other nodes that the resource is not available; selecting a next optimized collective operation; and performing the next optimized collective operation.

Abstract: Certain example embodiments concern a computer-implemented method of processing a relational query in a database system. The relational query addresses a plurality of data objects linked by one or more relationships. For each data object addressed by the relational query, at least one result is computed in accordance with at least one index structure, with the index structure being stored in a storage device of the database system. The results computed are merged in accordance with at least one translation data structure to produce a final result of the relational query, with the translation data structure representing the one or more relationships between the data objects and being stored in a memory of the database system.

Abstract: The invention is a method of optimizing the interaction between (i) a client, being an application such as database software, implemented on a computing device, and (ii) database server software implemented on a computing device. Query data is routed from the client to the database server software through an optimization system implemented on a computing device and then response data provided by the database server software is routed to the optimization system. The optimization system analyzes that (or later) query data and, based on that analysis, applies rules to response data provided by the database server software, in order to generate optimized response data to thereby speed up the interaction between the client and the database server software.

Abstract: A workload management service component of a parallel database-management system monitors usage of computational resources in the parallel database-management system. The component provides a query-processing-task-management interface and a query-execution engine. The engine receives query-processing requests associated with one of a number of services from host computers, and accesses the workload-management-services component to determine whether to immediately launch execution of query-processing tasks corresponding to the received query-processing requests. Alternatively, the engine accesses the component to place the query-processing requests on wait queues for subsequent execution. The determination is based on the current usage of computational resources within the parallel database-management system.

Abstract: Operations performed by a software application instance executed by a computing device are monitored. A determination is made that a particular operation performed matches an application signature representing a particular software application. In response, a match score is added to a total score for the software application. In response to determining that the total score is greater than or equal to a threshold, the software is classified.

Abstract: A first workload that contains logged predicates contained in database queries is received. A subset of the predicates is selected based on costs associated with the predicates. A compressed workload is formed using the selected subset of the predicates. Indexes are then selected based on the compressed workload.

Abstract: A method, device, and non-transitory computer-readable storage medium are provided for efficiently registering a relational schema. In co-compilation and data guide approaches, a subset of entities from schema descriptions are selected for physical registration, and other entities from the schema descriptions are not physically registered. In the co-compilation approach, a first schema description references a second schema description, and the subset includes a set of entities from the second schema description that are used by the first schema description. In the data guide approach, the subset includes entities that are used by a set of structured documents. In a pay-as-you-go approach, schema registration includes logically registering entities without creating relational database structures corresponding to the entities. A database server may execute database commands that reference the logically registered entities.

Abstract: Queries may be processed more efficiently in an massively parallel processing (MPP) database by locally optimizing the global execution plan. The global execution plan and a semantic tree may be provided to MPP data nodes by an MPP coordinator. The MPP data nodes may then use the global execution plan and the semantic tree to generate a local execution plan. Thereafter, the MPP data nodes may select either the global execution plan or the local execution plan is accordance with a cost evaluation.

Abstract: Distributing rows of data in a distributed table distributed across a plurality of nodes. A method includes identifying skewed rows of a first table to be distributed in a distributed database system. The skewed rows include a common data value in a column such that the skewed rows are skewed, according to a predetermined skew factor, with respect to other rows in the first table not having the common data value. Non-skewed rows of the first table that are not skewed according to the skew factor are identified. The skewed rows of the first table are distributed across nodes in a non-deterministic fashion. The non-skewed rows of the first table are distributed across nodes in a deterministic fashion. The rows of the first table distributed across the nodes, whether distributed in a deterministic fashion or non-deterministic fashion, are stored in a single table at each of the nodes.

Abstract: In one implementation, a query is received that is related to data stored in a database that is implemented in computer memory. Based on the received query, attributes of data stored in the database that are relevant to generating a response to the received query are identified. Information that is indicative of attributes for which values are recorded in different tables included in the database is accessed. Based on having accessed this information, tables included in the database that record values for the attributes identified as being relevant to generating a response to the received query are identified. These tables then are joined to create, within computer memory, a new table that reflects relationships between values of attributes identified as being relevant to generating a response to the received query.

Abstract: A computer system executes a user-supplied query across multiple relational database tables linked by a common key. A new query form, called a composite join, takes a user-supplied query including one or more terms optionally joined by logical operations, an identification of two or more tables and an identification of a common join key shared across the tables. The composite join applies the query across the tables such that any of the query terms can be matched by any of the tables. A query is performed across all tables for each query term and any join keys associated with matching records from the tables are identified in a set of join keys associated with the respective term. The logical operations are then performed on the resulting sets of join keys to combine the results of the term queries according to the user query.

Abstract: An apparatus for conducting a hierarchical join on a hierarchically clustered data stream is disclosed. The apparatus may include a memory storing query conditions that each determine whether a Structured Query Language query is suitable for performing a non-buffering read operation on a hierarchical data storage. A processor in communication with the memory may be configured to receive a Structured Query Language (“SQL”) query from a client device and evaluate the SQL query for one or more of the query conditions stored in the memory. When the processor determines that the SQL query satisfies one or more of the query conditions, the processor may then perform a non-buffering read operation on the hierarchical data storage to obtain a hierarchically clustered data stream. The hierarchically clustered data stream may be evaluated to obtain a plurality of record results, which may be transmitted to the client device.

Abstract: Methods for generating a query input string include sorting a first input relation and a second input relation in order from the first relation to the second relation. The second input relation is concatenated to the first input relation, and the concatenated input relations are stored in a single string.

Abstract: According to one embodiment of the present invention, a system partitions data for parallel processing and comprises one or more computer systems with at least one processor. The system partitions data of a data object into a plurality of data partitions within a data structure based on a plurality of keys. The data structure includes a plurality of dimensions and each key is associated with a corresponding different dimension of the data structure. Portions of the data structure representing different data partitions are assigned to the computer systems for parallel processing, and the assigned data structure portions are processed in parallel to perform an operation. Embodiments of the present invention further include a method and computer program product for partitioning data for parallel processing in substantially the same manner described above.

Abstract: A subscription to multiple channels of information on a single topic is performed. A topic of interest is received via a user interface. A user interface element is presented via the user interface to facilitate a user subscription to a plurality of channels associated with the topic of interest without having to subscribe separately to each channel. A user selection of the user interface element is received and a user is subscribed to the plurality of channels in response to the received user selection.

Abstract: Embodiments of the invention provide techniques for generating predicted cardinality statistics for grouped aggregation functions included in database queries. In general, characteristics of a database query are determined, and are then supplied to a probability function configured to generate a predicted cardinality statistic. The generated statistic represents a prediction of the probable cardinality of the results of a grouped aggregation function in the event that the query is executed. The predicted cardinality statistic may be used by a query optimizer to determine an efficient query plan for executing the database query.

Abstract: A distributed database management system maintains logical collections of data. The collections may grow at varying rates, and may place storage and workload processing demands on the system that change over time. A value representative of the current maximum of capacity utilization for computing nodes in the system may be calculated. An estimate of the number of days for each computing node to reach the current maximum may be calculated, and compared to an average number of days. Computing nodes whose number of days is above the average may be selected to receive new logical collections of data.

Abstract: Provided are techniques for receiving a record, wherein the received record has a space-time feature, selecting candidate entities using the space time feature, performing space time analysis to determine whether the received record should be conjoined with a candidate entity from the candidate entities, and, in response to determining that the received record should be conjoined with the candidate entity, making an entity resolution assertion by conjoining the received record and the candidate entity to form a newly conjoined entity.

Abstract: According to one embodiment of the present invention, a system partitions data for parallel processing and comprises one or more computer systems with at least one processor. The system partitions data of a data object into a plurality of data partitions within a data structure based on a plurality of keys. The data structure includes a plurality of dimensions and each key is associated with a corresponding different dimension of the data structure. Portions of the data structure representing different data partitions are assigned to the computer systems for parallel processing, and the assigned data structure portions are processed in parallel to perform an operation. Embodiments of the present invention further include a method and computer program product for partitioning data for parallel processing in substantially the same manner described above.

Abstract: A system joins predicate evaluated column bitmaps having varying lengths. The system includes a column unifier for querying column values with a predicate and generating an indicator bit for each of the column values that is then joined with the respective column value. The system also includes a bitmap generator for creating a column-major linear bitmap from the column values and indicator bits. The column unifier also determines an offset between adjacent indicator bits. The system also includes a converter for multiplying the column-major linear bitmap with a multiplier to shift the indicator bits into consecutive positions in the linear bitmap.

Abstract: A database language is extended to define constraints on a data model (e.g., entity-relationship model) rather than the concrete database. The constraints can be declarative (e.g., constraints that are defined using expressions of the database language) or programmatic (e.g., constraints that are defined as a stored procedure implemented in a domain specific language). By storing the constraints at a higher level than the database level, the constraints can be performed without changing the persistency of the database. Also disclosed are techniques for handling of constraints on partially loaded entities.

Abstract: Facilitating identification of star schemas in database environments. In an embodiment, queries directed to relational database tables (organized according to normalized schema) are examined to determine the relationships specified in the queries. A star schema is then generated by including the specified relationships. A data warehouse may be organized according to the generated star schema and the data previously stored in the database tables may be copied to the data warehouse.

Abstract: A system and method for performing a query operation on a pair of relations in a database system coupled to a heterogeneous system (HS) is disclosed. Assuming that that pair of relations is partitioned and already loaded into the HS, the database system receives a query on the pair of relations and based on the type of query operation computes the cost of performing the query operation on the database alone or the costs of performing the query operation with the assistance of the HS, each of the costs corresponding to a particular algorithm. If the costs indicate that the HS improves the performance of the query operation, then the HS computes portions of the operation, and returns the results back to the database system. If any parts of the relation are out of sync with the database system, the database system performs operations to maintain transactional consistency.

Abstract: A system, method, and computer program product are provided for performing a join operation between a local table at a local server and a remote table at a remote server. In accordance with an embodiment of the present invention, a query instruction to join the local table and the remote table is received at the remote server. Qualifying rows of the local table are then retrieved to the remote server, and the remote table is joined with the qualifying rows to generate a result table, which is then sent to the local server.

Abstract: In one embodiment, a computer-implemented method comprises receiving a query. A data store stores data as a plurality of data sets. Each data set comprises a plurality of fields and a plurality of data elements. Each field is associated with a portion of data elements. The query identifies selected data sets and selected properties of the selected data sets. For each selected property, the data elements of the selected data sets associated with each selected property are determined. A first rating of the determined data elements of the selected data sets is determined based on a type of combination of a pair of selected data sets. For the selected data set pairs, a second rating of the pair is determined based on the first ratings for the selected properties. A model of a combination of the selected data sets is generated based on the second rating.

Abstract: According to some embodiments, an anchor transactional view may be defined for at least one business object data structure. The anchor transactional may have a plurality of anchor fields, each anchor field representing a data source and being associated with a field of an anchor search view. An indication of at least one extension field to the anchor search view may be received. The anchor search view and at least one extension field may represent, for example, a virtual fast search infrastructure view. Responsive to the received indication of the at least one extension field, an additional view may be dynamically joined at runtime to the anchor transactional view. The additional view may have at least one additional field, and each additional field may be associated with one of the extension fields.

Abstract: The present invention provides a system and method for optimizing reduce-side join operation in a map-reduce framework. The system and method executing one or more map operations on the second data structure, grouping the data tuples to a single region of the second data structure, providing the grouped data to a single reducer and, selecting one of scan approach and a look-up approach by one or more reducers based on region key count value and pre-determined conditions of the user.

Abstract: A database system rewrites database queries based on rewrite constraints specification. The rewrite constraints specification provides directives to the database system to generate temporary tables for storing intermediate results of database queries and rewrite the corresponding database queries in terms of the temporary tables. The subqueries for matching the rewrite constraints specification may be specified in various ways. For example, the rewrite constraints specification may identify the subqueries by using one or more aliases. The rewrite constraints specification may specify a list of tables such that all database queries that join the database tables specified in the rewrite constraints specification are determined to match. The optimizer is able to optimize the rewritten database queries better by getting a better estimate for the statistics describing the temporary tables.

Abstract: A database system allows users to specify plan constraint specification that limit choices of execution plans considered by an optimizer of the database system for optimizing database queries. The plan constraint specification specifies attributes of execution plans. The plan constraint specification may identify tables/intermediate results that the plan constraint is applicable to using table names or aliases. The database system applies the plan constraint specification to database queries that match the tables/aliases specified in the plan constraint specification. The database system limits the choice of execution plans evaluated for a database query to execution plans satisfying the attributes specified in an applicable plan constraint specification. The plan constraint specification may specify distribution of a table, a join order for tables, the join mechanism, cardinality of a table or intermediate result, and so on.

Abstract: Systems and methods are disclosed for query processing in a big data analytics platform by enumerating plans for a current query using a processor; building a dominance graph for the current query; for each plan, determining a regret value and a score for the plan based on the regret value and cost; and selecting query plans in an online fashion for query processing in big data analytics platforms where intermediate results are materialized and can be reused later.

Abstract: Techniques are disclosed for accessing a dimensional data model when processing a query. In one embodiment, the query is processed by performing a two-stage zigzag join operation including a zigzag main join and a zigzag back join. The zigzag main join is configured to generate a set of row identifiers of fact records satisfying any local predicates in the query. The zigzag back join is configured to generate query results based on the set of row identifiers. The query results are returned responsive to the query.

Abstract: An approach is provided for providing search with contextual processing. A contextual search platform processes and/or facilitates a processing of one or more data requests data to generate at least one query. The contextual search platform further determines one or more algorithms for bounding, at least in part, result data responsive to the one or more data requests, the at least one query, or a combination thereof. The contextual search platform also causes, at least in part, an association of the one or more algorithms with the at least one query.

Abstract: Some embodiments provide a method for managing a logical switching element that includes several logical ports. The logical switching element receives and sends data packets through the logical ports. The logical switching element is implemented in a set of managed switching elements that forward data packets in a network. The method provides a set of tables for specifying forwarding behaviors of the logical switching element. The method performs a set of database join operations on the tables to specify in the tables that the logical forwarding element drops a data packet received through a first logical port when the data packet is headed to a second logical port different than the first logical port.

Abstract: A query complier analyzes a query to identify a correlated scalar subquery. The query complier transforms the query having the correlated scalar subquery into a query of AGGREGATION INNER/OUTER JOIN or MAX1ROW INNER/OUTER JOIN depending on a result type of the correlated scalar subquery. The AGGREGATION INNER/OUTER JOIN performs JOIN on the rows of the correlated scalar subquery with the rows of a main query and AGGREGATE on the joined rows and returns a result of the joined rows of the main query and aggregation value thereof. The MAX1ROW INNER/OUTER JOIN performs JOIN on the rows of the correlated scalar subquery with the rows of a main query, raises Error when the number of joined rows of the subquery is two or more and returns a result of the row of the main query and the joined row of the subquery.

Abstract: A database server receives a query from a remote application server that is associated with a calculation scenario. The calculation scenario defines a data flow model that includes one or more calculation nodes that each define one or more operations to execute on the database server. The database server can be a column-oriented database and at least one of the calculation nodes comprises at least one join operation. Thereafter, the database server instantiates the calculation scenario so that it is optimized by removing one or more join operations and associated branches within the calculation scenario. The database server then executes the operations defined by the calculation nodes of the optimized calculation scenario to result in a responsive data set. The database server then provides the data set to the application server.

Abstract: A query is received by a database server from a remote application server. The query is associated with a calculation scenario that defines a data flow model that includes one or more calculation nodes and that includes at least one hierarchy filter. Each hierarchy filter is a filter of at least one hierarchy table. Each calculation node defines one or more operations to execute on the database server. Thereafter, the database server instantiates the calculation scenario. The instantiating includes optimizing the calculation scenario by transforming at least one hierarchy filter and pushing down the at least one transformed hierarchy filter to a lower calculation node. The database server then executes the operations defined by the calculation nodes of the optimized calculation scenario to result in a responsive data set. The database server can subsequently provide the data set to the application server.

Abstract: A query associated with a calculation scenario comprising a plurality of calculation nodes can be received by a calculation engine. The calculation scenario is instantiated and the query is transformed into a convex hull filter based on the at least one multiple selection condition that can be executed at any of the calculation nodes. The instantiated calculation scenario and the convex hull filter are executed to provide a result set. Related apparatus, systems, methods, and articles are also described.

Abstract: A method of identifying one or more particular images from an image collection, includes indexing the image collection to provide image descriptors for each image in the image collection such that each image is described by one or more of the image descriptors; receiving a query from a user specifying at least one keyword for an image search; and using the keyword(s) to search a second collection of tagged images to identify co-occurrence keywords. The method further includes using the identified co-occurrence keywords to provide an expanded list of keywords; using the expanded list of keywords to search the image descriptors to identify a set of candidate images satisfying the keywords; grouping the set of candidate images according to at least one of the image descriptors, and selecting one or more representative images from each grouping; and displaying the representative images to the user.

Abstract: A system and method for improving performance of join operations is disclosed. The method in one embodiment includes building a graph of vertices and edges, which represent the tables and join conditions for a particular database schema. The method then traverses the graph to find a set of candidate join operations. The method further includes selecting from the set of subset of join operations that makes the best use of a given amount of memory, which means finding a collection of denormalizations which when residing in memory provide the most benefit and the least cost for the given amount of memory. The method then deploys the denormalizations so that current queries in a query processing system can use them instead of actually performing the joins.

Abstract: A system gathers information on influential people and builds a social graph. The system is flexible in what types of information it gathers so that a detailed picture on influential persons can be determined. The information is organized to allow users of the system to make fast searches with the system and draw meaningful conclusions from the information.

Abstract: A system and method for processing a database query may include determining a set of tables referenced in a query; representing the set of tables by vertices of a graph; and, if the graph is incomplete, then determining the query is associated with a shard conflict. A system and method may determine a query is not associated with a shard conflict if, and only if, the graph is complete.

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: Various embodiments of systems and methods for tracking queries and retrieved results are described herein. In one aspect, a first query is associated with a first result set in a first tuple and a second query is associated with a second result set in a second tuple. The first result set is retrieved based on the execution of the first query and the second result set is retrieved based on the execution of the second query. The first and the second tuples are retained in a data structure in the order of execution of the respective queries. The retrieved result sets may be accessed forwards or backwards along the data structure without re-execution of the queries.

Abstract: A computer determines that the type of one or more of a relational operator and operands of a relational expression originated in a first type system, and determines the sign of at least one of the operands. The computer rewrites the relational expression based on the sign of at least one of the operands, sends the rewritten relational expression for evaluation in a second type system, and receives the evaluated rewritten relational expression after evaluation in the second type system. The computer can rewrite the relational expression by generating a group of terms joined disjunctively, as well as by generating a group of conjunctive terms joined disjunctively.

Abstract: Described herein is a technology for facilitating optimization of database queries is described herein. In some implementations, a first query is received. At least one scenario for optimization is automatically recognized by detecting specific syntax in the query. A second query is then automatically generated by re-writing the first query using a pre-defined operation corresponding to the recognized scenario.