Abstract: Disclosed is method for processing an aggregate function. Rows that contain a reference to intermediate result structures are grouped to form groups. For each group, aggregate element structures are formed from the intermediate result structures and, if the aggregate function specifies ordering, the aggregate element structures are sorted based on a sort key.

Abstract: Provided are a techniques for processing a query including semi-joins. At execution time, a next semi-join is selected from the semi-joins for execution in a current round of semi-join executions. A reporting threshold is determined that indicates a number of record-identifiers to be retrieved for the determined semi-join. The selected semi-join is executed until the determined number of record identifiers are retrieved.

Abstract: A method, storage server, and computer readable medium for off-loading star-join operations from a host information processing system to a storage server. At least a first and second set of keys from a first and second dimension table, respectively are received from a host system. Each of the first and second set of keys is associated with at least one fact table. A set of locations associated with a set of foreign key indexes are received from the host system. A set of fact table indexes are traversed. At least a first set of Row Identifiers (“RIDs”) associated with the first set of keys and at least a second set of RIDs associated with the second set of keys are identified. An operation is performed on the first and second sets of RIDs to identify an intersecting set of RIDs. The intersecting set of RIDs are then stored.

Abstract: A method for executing a query to access data stored in a database, wherein the query includes a plurality of DISTINCT keys, is disclosed. The method of the present invention includes providing a first DISTINCT operation on a first DISTINCT key, storing data fetched from the first DISTINCT operation in a master workfile if more than one sort process is needed to execute the query, and utilizing the master workfile to perform subsequent DISTINCT operations for the other DISTINCT keys.

Abstract: A system and computer readable medium for executing a query to access data stored in a database, wherein the query includes a plurality of DISTINCT keys, is disclosed. The system and computer readable medium includes a capture module for identifying each of the plurality of DISTINCT keys in the query and a sort module coupled to the capture module for determining if more than one sort is needed to execute the query, performing a first DISTINCT operation on a first DISTINCT key of the plurality of DISTINCT keys, storing data fetched from the first DISTINCT operation in a master workfile only if more than one sort process is needed to execute the query, and utilizing the master workfile to perform subsequent DISTINCT operations on the other of the plurality of DISTINCT keys.

Abstract: An XML schema is compiled into an annotated automaton encoding, which includes a parsing table for structural information and annotation for type information. The representation is extended to include a mapping from schema types to states in a parsing table. To validate a fragment against a schema type, it is necessary simply to determine the state corresponding to the schema type, and start the validation process from that state. When the process returns to the state, fragment validation has reached successful completion. This approach is more efficient than a general tree representation. Only the data representation of the schema information is handled, making it much easier than manipulating validation parser code generated by a parser generator. In addition, only one representation is needed for schema information for both document and fragment validation. This approach also provides a basis for incremental validation after update.

Abstract: An XML schema is compiled into an annotated automaton encoding, which includes a parsing table for structural information and annotation for type information. The representation is extended to include a mapping from schema types to states in a parsing table. To validate a fragment against a schema type, it is necessary simply to determine the state corresponding to the schema type, and start the validation process from that state. When the process returns to the state, fragment validation has reached successful completion. This approach is more efficient than a general tree representation. Only the data representation of the schema information is handled, making it much easier than manipulating validation parser code generated by a parser generator. In addition, only one representation is needed for schema information for both document and fragment validation. This approach also provides a basis for incremental validation after update.

Abstract: A method and system for evaluating a path query are disclosed. The path query corresponds to a query tree including a plurality of query nodes. At least one query node corresponds to at least one predicate and is at a level. The predicate(s) are evaluated for previous query node(s). The method and system include scanning data nodes of a document and determining if the data nodes match the query nodes. The method and system also include placing data related to the data node in match stacks corresponding to matched query nodes. The data for the query node(s) include attribute(s) corresponding to the predicate(s). The method and system further include propagating a matching of the at least one query node backward to a matching of the at least one previous query node.

Abstract: Techniques are provided that determine that a query includes at least one subquery that may be correlated or decorrelated. An internal representation of the query that represents the subquery in both correlated and decorrelated form is generated, wherein the internal representation includes at least one virtual table.

Abstract: Techniques are provided that determine that a query includes at least one subquery that may be correlated or decorrelated. An internal representation of the query that represents the subquery in both correlated and decorrelated form is generated, wherein the internal representation includes at least one virtual table.

Abstract: A method, computer program product, and system for managing row identifier (RID) list processing on an index are provided. The method, computer program product, and system provide for accessing one or more key values in the index based on one or more keys specified in a query, retrieving a plurality of row identifiers corresponding to the one or more key values from the index, and predicting an actual number of row identifiers to be retrieved from the index based on the one or more key values accessed and the plurality of row identifiers retrieved.

Abstract: A method and system for evaluating a path query are disclosed. The path query corresponds to a query tree including a plurality of query nodes. At least one query node corresponds to at least one predicate and is at a level. The predicate(s) are evaluated for previous query node(s). The method and system include scanning data nodes of a document and determining if the data nodes match the query nodes. The method and system also include placing data related to the data node in match stacks corresponding to matched query nodes. The data for the query node(s) include attribute(s) corresponding to the predicate(s). The method and system further include propagating a matching of the at least one query node backward to a matching of the at least one previous query node.

Abstract: Disclosed is method for processing an aggregate function. Rows that contain a reference to intermediate result structures are grouped to form groups. For each group, aggregate element structures are formed from the intermediate result structures and, if the aggregate function specifies ordering, the aggregate element structures are sorted based on a sort key.

Abstract: Disclosed is a method, system, and program for processing an aggregate function. Rows that contain a reference to intermediate result structures are grouped to form groups. For each group, aggregate element structures are formed from the intermediate result structures and, if the aggregate function specifies ordering, the aggregate element structures are sorted based on a sort key.

Abstract: Provided are a techniques for processing a query including semi-joins. At execution time, a next semi-join is selected from the semi-joins for execution in a current round of semi-join executions. A reporting threshold is determined that indicates a number of record-identifiers to be retrieved for the determined semi-join. The selected semi-join is executed until the determined number of record identifiers are retrieved.

Abstract: A method and system for using a procedure residing and executed entirely within a database system is disclosed. The procedure utilizes at least one variable, which has a plurality of attributes. The method and system include defining the at least one variable as at least one global variable prior to calling of the procedure. Defining the global variable(s) includes informing the database system of the plurality of attributes of the variable(s) and allowing the database system access to the at least one variable. The method and system also include tracking the global variable(s).

Abstract: A method and system for providing a scalable storage scheme for native hierarchically structured data of relational tables, includes a base table with indicator columns with information pertaining to hierarchically structured data of a document, data tables for storing the hierarchically structured data corresponding to the indicator columns, and node identifier indexes corresponding to the data tables for mapping between the indicator columns and the hierarchically structured data in the data tables. In an embodiment, actual data for each hierarchically structured data (such as XML) column is stored in a separate data table, and each data table has a separate node identifier index. The node identifier index is searched with a key containing the document identifier and a logical node identifier is used, and a record identifier of a record in the data table containing the node assigned the logical node identifier is retrieved.

Abstract: A storage of nodes of hierarchically structured data uses logical node identifiers to reference the nodes stored within and across record data structures. A node identifier index is used to map each logical node identifier to a record identifier for the record that contains the node. When a sub-tree is stored in a separate record, a proxy node is used to represent the sub-tree in the parent record. The mapping in the node identifier index reflects the storage of the sub-tree nodes in the separate record. Since the references between the records are through logical node identifiers, there is no limitation to the moving of records across pages, as long as the indices are updated or rebuilt to maintain synchronization with the resulting data pages. This approach is highly scalable and has a much smaller storage consumption than approaches that use explicit references between nodes.