International Business Machines Corporation

Compaq Computer Corporation, Inc.

Hewlett-packard Development Company, L.p.

Compaq Information Technologies Group, L.p.

Robbert C Van Der Linden

Johannes Klein

Raj K Rathee

Brian Shaun Vickery

Henrik Loeser

Hansjorg Zeller

Daniel T Chang

Mary C Lehner

Bruce A Benfield

Sundararaman Saiprasad

Satoshi Hada

Edison Lao Ting

Michiharu Kudo

Akihiko Tozawa

Naishin Seki

Mayank Pradhan

Anoop Sharma

A method, computer readable medium, and system for processing a structured document are disclosed. The method, computer readable medium, and system include identifying a plurality of strings processed by a database, assigning an identifier to each of the plurality of strings, storing each of the plurality of strings and its assigned identifier in a table in the database, and utilizing the table during document processing.

Processing structured documents stored in a database

An improved method and system for providing path-level access control to a structured document in a collection stored in a database, where the structured document includes a plurality of nodes is disclosed. The method includes the steps of providing an access control policy for the collection, where the access control policy comprises a plurality of access control rules, generating a path for each node of the plurality of nodes in the document, and generating for each path associated with a node a corresponding value expression based on at least one access control rule of the plurality of access control rules. According to the method and system of the present invention, the corresponding value expression is utilized during access control evaluation to determine whether a user is allowed to access a node in the structured document.

Method and system for providing path-level access control for structured documents stored in a database

An improved method and system for performing path-level access control evaluation for a structured document in a collection, where the structured document includes a plurality of nodes and each of the nodes is described by a path, is disclosed. The method comprises providing a cache for temporarily storing a cache entry for a path associated with a node of the plurality of nodes, receiving a query that includes a request to access the node, checking the cache entry for the path associated with the node, and determining whether to grant access to the node based on the cache entry.

Method and system for utilizing a cache for path-level access control to structured documents stored in a database

A method and system for distributed garbage collection in a pipelined workflow environment comprising a plurality of processing nodes that pass item references to each other. Each node maintains a reference list of local item references and a reference dictionary of remote item references, and periodically synchronizes the reference list with the reference dictionaries of other nodes in the workflow, so that item references are not marked for garbage collection while other processing nodes may still have outstanding references to them.

Distributed garbage collection in a dataflow system

Disclosed is a system and program for managing schemas. A schema and one or more associated schema documents are registered. A schema information document is automatically generated based on the schema and the one or more associated schema documents. A request to be performed on at least one of the schema, an associated schema document, and the schema information document is processed.

Schema management

A method for processing a structured document are disclosed. The method includes identifying a plurality of strings processed by a database, assigning an identifier to each of the plurality of strings, storing each of the plurality of strings and its assigned identifier in a table in the database, and utilizing the table during document processing.

Method for processing structured documents stored in a database

Disclosed is a method, system, and program for managing schemas. A schema and one or more associated schema documents are registered. A schema information document is automatically generated based on the schema and the one or more associated schema documents. A request to be performed on at least one of the schema, an associated schema document, and the schema information document is processed.

An improved method and system for processing a structured document stored in a database is disclosed. The method includes identifying strings that are processed by the database, assigning an identifier to each of the strings, storing each of the strings and the assigned identifier in a table in the database, where the table is a global database table, and utilizing the table to replace the strings with their assigned identifiers throughout the database, where the identifiers are used during document processing.

Method and system for processing structured documents in a native database

The SQL compiler and SQL executor in a database management system are extended to process queries requiring streaming mode processing of data stored in a table. A scan operator performs table access functions during execution of the streaming mode query. The scan operator first performs an initial scan to access rows in a specified database table, and then performs a delta scan to access new rows added to the table, as well as rows modified by other queries. The scan operator continues to process new data added to the table until the initiating user or application closes the associated cursor. A set of data structures are provided to keep track of active scan operators, including a session control block that includes fields for keeping track of whether the scan operator is performing an initial scan or a delta scan. The session control block also includes, for streaming mode scan operators, a delta scan list of new and modified rows to be processed in the delta scan. When a transaction terminates, any streaming mode scan operators whose operation was suspended because of rows locked by the transaction are automatically rescheduled for execution.

System and method for performing database operations on a continuous stream of tuples

The SQL compiler and SQL executor in a database management system are extended to execute statements for dequeuing rows from a database table and statements that both updating tuples and return those tuples to a calling application. During execution of a select statement that includes an embedded update or delete operation, a table access operator accesses a defined range of rows in a database table. The table access operator receives from a calling application a request for rows dequeued from the database table. The table access operator responds to the requests for rows by returning to the calling application qualifying rows, if any, from the database table and also by performing the embedded delete or update operation. The SQL executor returns control to the calling application only after all rows deleted or updated by the table access operator have been sent to the calling application.

Database management system and method for dequeuing rows published to a database table

A database management system includes an execution engine that, upon rollback of an aborted transaction, has the ability to set fields of the rows that are updated or deleted by the transaction prior to aborting. In particular, when a select, update or delete statement includes a &ldquo;set on rollback&rdquo; clause, the respective table access operator of the execution engine modifies the &ldquo;before image&rdquo; of each row that is stored by the transaction log manager. The modified before image includes the field updates specified by the set on rollback clause. If a transaction associated with the statement aborts, when the transaction log manager restores the before images of each row that was deleted or updated by the transaction, the restored before images include the field updates specified by the set on rollback clause.

Database management system and method for updating specified tuple fields upon transaction rollback

In a database management system, when the table to be accessed by a statement is partitioned, a respective partition scan operator is used to access rows of each respective database table partition. A fan out operator receives requests from a calling application to access rows from table, and responds by sending requests for rows to the partition scan operators. It receives rows of the table from the partition scan operators and sends the received rows of the database table to another node in the execution tree. Each of the partition scan operators responds to the requests for rows by returning to the fan out operator qualifying rows, if any, from the corresponding table partition. If the statement being executed includes an embedded delete or update operation, the qualifying rows are deleted or updated at the same time that the qualifying rows are returned to the fan out operator. Control is returned to the calling application only after all rows deleted or updated by the partition scan operators have been sent to the calling application. When the statement being executed is a streaming mode query, the fan out operator sends non-blocking requests to the partition scan operators so that when one access to one partition is blocked, rows from another partition are processed.

Database management system and method for accessing rows in a partitioned table

A database management system is extended to process SQL statements so as to skip over rows that are locked in conflicting modes. Normally, a table access operator is blocked when it attempts to access a row that is locked in a conflicting mode, such as a write lock mode, that is inconsistent with the read or write access required by the operator. Generally, the lock in the conflicting mode will be held by a transaction other than the transaction associated with the operator in question. When the SQL statement being executed uses the &ldquo;skip conflict&rdquo; syntax provided by the present invention, the operator skips over rows that are locked in conflicting modes, which would otherwise cause the operator to suspend operation. Furthermore, if the operator is operating in streaming mode, a key that identifies such skipped rows is added to the operator's list of rows to be processed at a later time.

Growing community of inventors

Scotts Valley, CA, United States of America

Robbert C Van Der Linden