Abstract: A method and apparatus are provided for implementing a content based publish-and-subscribe system in a relational database system. A subscriber may request for messages by using a query language supported by the database server. The queries are then used as subscription rules for determining whether an incoming message is to be sent to the subscriber. Evaluation of incoming messages against subscription rules involves a two-tier process. The first tier involves filtering out all the subscription rules that could not possibly apply to the incoming message. The second tier involves further evaluation of the incoming message, if needed, to determine which subscribers are to receive the incoming message. In another aspect of the embodiment, in cases where the publisher is the relational database system itself, queries that request for messages are not stored as subscription rules because publication of the messages is implicit.

Abstract: A search and retrieval system pre-processes an input query to map a contextual semantic interpretation, expressed by the user of the input query, to a boolean logic interpretation for processing in the search and retrieval system. A knowledge base comprises a plurality of categories, such that subsets of the categories are designated to one of a plurality of groups. A lexicon stores a plurality of terms including definitional characteristics for the terms. To pre-process the query, the search and retrieval system receives an input query comprising a plurality of terms, and processes the terms by referencing the lexicon to identify value terms that comprise a content carrying capacity. The knowledge base is referenced to identify a group for each value term.

Abstract: A method and apparatus for managing access to a resource using anticipatory lock conversions in a distributed lock management system is provided. According to the method, when an entity requests a lock on a resource, the entity is granted, if possible, a lock with a more restrictive lock mode than is required if it is determined that the entity may require the more restrictive lock mode in the near future.

Abstract: A system and method for managing storage from multiple data storage devices are disclosed. The system and method provide improved load balancing, reduction or elimination of fragmentation, and efficient changes in hardware configurations. I/O load and data are spread relatively evenly across many data storage devices in the storage system. Dynamic reorganization can be performed for the data stored on the data storage devices.

Abstract: A technique for database management includes receiving an indication of a selected scope of a trigger. The scope is selected from a plurality of scopes of database management. The scope can be on the level of an individual table, or a schema associated with a user, or the database itself, or a system of databases, among others. The technique also includes receiving an indication of a selected event that belongs to the set of one or more events associated with the selected scope. Trigger metadata is stored that identifies both the selected scope and the selected event. A technique is also described for executing a process in this database management system. Flags indicative of one or more applicable events of the selectable events are loaded into a private cache of the process and checked when a new event occurs.

Abstract: A method and system for associating properties in a computer system is described. An aspect relates to a mechanism for dynamically determining the value of a property for an instance or object, which can override the property defined for the class or object type. Another aspect relates to a mechanism for dynamically changing at run-time the set of properties associated with system structures, such as classes, object types, instances, or objects. Yet another aspect relates to a mechanism that can associate or disassociate an entire set of properties at the same time, rather than having to separately associate or disassociate each property within a set of properties. A further aspect relates to a mechanism for allowing particular instances or objects to explicitly not inherit properties of its familial class or object type.

Abstract: According to an approach for propagating messages in a distributed computer system, message information is identified that needs to be sent to a destination site. After the message information is identified, the message information is assigned a propagation sequence number that identifies when the message information is sent to the destination site relative to other message information sent from the source site to the destination site. A message that is based on the message information is then transmitted to the destination site. The transmitted message includes the sequence number value and a source ID that identifies the source site as transmitting the message to the destination site. After the message is received at the destination site, the propagation sequence number that was assigned to the message information may be stored in nonvolatile memory at the destination site.

Abstract: Techniques are described for reducing the number of sort operations required for a query that contains window functions. The techniques involves determining a set of Partition By and Order By clause pairs that corresponds to the set of window functions and then grouping the Partition By and Order By clause pairs into Ordering Groups where each Ordering Group may be satisfied by a single sort operation. From the set of Ordering Groups, a minimal set of Ordering Groups is determined. The techniques account for the interaction of orderings from Group By and Order By clauses in the query block.

Abstract: A method and apparatus for managing access to resources is provided. When a process requires access to a resource, the process requests a lock on the resource from a lock manager unit that resides on the same node as the process. If a resource object for the resource does not exists, one is created in the lock manager unit, but not on lock manager units on other nodes. Because each lock manager unit does not have to store all resource objects, and resource objects are only created for resources that are actually used, the overhead of the lock management system is significantly reduced. Resources are grouped in recovery domains. When a lock manager unit that supported a recovery domain fails, the recovery domain is marked invalid. All resources in the recovery domain are considered invalid unless it would have been impossible for a failed instance to have held an exclusive lock on the resource. A snapshot of lock information is made before cleanup is performed on invalid resources.

Abstract: A system and method for indexing and storing multi-dimensional or multi-attribute data. Data items are recursively sorted in a selected dimension (e.g., the dimension having the greatest variance) and divided until each subdivision fits into a leaf node having a specified fanout. Intermediate nodes and a root node are constructed to complete the index. Each node of the index is stored in a database as a separate object or record and may include a node identifier of the unique, an identifier of a parent and/or a sibling node and an entry for each child of the node, which may be data items or other nodes. Each record entry for a child includes an associated bounding area encompassing descendant data items. Another database table or module may store information about the index, such as the dimensionality of the data, the index fanout and an identifier of a root of the index.

Abstract: A method and system are provided for handling within a database system data items that are associated with data types that are not supported by the database language used to the database system. The data types are registered with the database system by storing, in the database, metadata that indicates the structure, physical layout, and constraints that apply to the data types. The database system uses the structure and physical layout information to access individual elements of data items. The database system validates data items using the constraint information, which includes constraints that dictate what values are valid for certain elements based on what values are supplied for other elements. Data items associated with many different data types may be stored in the same table. Applications can access the data items through a transformation view that transforms the data items from their native format to a format expected by the applications.

Abstract: A method and apparatus for buffering is provided. A set of buffers is maintained in an ordered list based on a profit value generated for each buffer. The profit value for a buffer reflects multiple access characteristics of the buffer. The list of buffers is partitioned into divisions referred to as buckets. Each bucket contains a set of buffers and is associated with a subrange of the fall range of profit values that may be generated. The bucket that covers the very top of the list is associated with highest profit value subrange, the bucket that covers the bottom of the list is associated with the lowest profit value subrange. When data is first placed in a buffer, the buffer's position within the buffer list is not immediately based on its profit value. Instead, an access history is first accumulated for the buffer and, once accumulated, the buffer's profit value earns the buffer's place in the list.

Abstract: A mobile-based client-server system architecture incorporates two specialized software layers—a specialized “proxy” layer that resides on a mobile client station, and a “web agent” layer that resides on a server. A conventional web browser application residing on a mobile client station is configured to point to the proxy layer, which captures HTTP information request messages that are transmitted to, and received from, the web browser. The HTTP request messages are packed by the proxy layer within a selected communication transmission format for upstream transmission over a communication network, such as a wireless network. At the server, the web agent layer recovers the original, (i.e., “raw”) HTTP request messages, which are then sent to an appropriate web server for further processing.

Abstract: A method and apparatus for identifying one or more schemas from which a Structured Query Language (SQL) statement may have been executed is provided. According to the method, to identify schemas from which a database command may have been executed a set of object references that are included in the database command is determined. From the set of object references, one or more ambiguous object references that are contained in the set of object references are identified. A set of one or more schemas that contain objects that correspond to each of the one or more ambiguous object references is then identified.

Abstract: According to an approach for providing communication between sub-applications in a vertical application, messages transmitted by sub-applications in message formats supported by the sub-applications are translated to produce messages in a predetermined common message format referred to herein as a “common view.” Messages to be received by sub-applications in the common view are translated to produce messages in the formats supported by the sub-applications. An adapter attached to each sub-application provides for the translation of messages between a message format supported by the sub-application to which it is attached and the common view.

Abstract: A method and system for optimizing the execution of database statement is described. An aspect is related to providing a framework for the creation, association, and use of optimizer-related functions to calculate the cost of execution plans involving non-native database entities. Examples of these optimizer-related functions include selectivity, statistics, and costs functions. Another aspect is related to the optimization of database statements having non-boolean predicates. Yet another aspect is related to the determination and use of different granularity levels of information for submitting database statement predicates to optimizer-related functions. Optimizer-related functions can also be defined for system-supplied objects and entities.

Abstract: A method and apparatus heats ultrapure water using microwaves. Chambers such as pipes containing the water are capable of admitting microwaves to the water, allowing the microwaves to heat the water. The pipes may be made of inert material such as PVDF or quartz that will not introduce contamination into the water.

Abstract: The present invention provides a method and apparatus for partitioning a buffer cache for dynamically mapping data blocks with a particular replacement strategy based on the associated table's access and/or usage patterns. According to the method, a buffer cache in a computer system is managed by dividing the buffer cache into multiple buffer pools. In managing the buffer cache, when a data item is requested, it is first determined whether the requested data item is stored in a buffer within the buffer cache. If the requested data item is not stored in a buffer in the buffer cache, then a particular buffer pool in the buffer cache is dynamically selected for storing the requested data item. Once the particular buffer pool is selected, the requested data item is stored into a buffer in the particular buffer pool.

Abstract: A method and apparatus for multi-phase locking for partition maintenance operations is provided. In the first phase, a shared data dictionary lock is acquired on a body of metadata in a data dictionary. Next, the data dictionary is read and a list of affected partitions is generated. In the second phase, an intent exclusive data lock is acquired on the affected table. Next, an exclusive data lock is acquired on the affected partitions of the affected table. The shared data dictionary lock on the data dictionary is released and a physical attribute of the data of the affected partitions is changed. In the third phase, an exclusive data dictionary lock is acquired on the data dictionary. The metadata associated with the affected partitions in the data dictionary is updated and the exclusive data locks on the affected partitions and the intent exclusive data lock on the affected table are released. Finally, the exclusive data dictionary lock on the data dictionary is released.

Abstract: An information retrieval system processes user input queries, and identifies query feedback, including ranking the query feedback, to facilitate the user in re-formatting a new query. A knowledge base, which comprises a plurality of nodes depicting terminological concepts, is arranged to reflect conceptual proximity among the nodes. The information retrieval system processes the queries, identifies topics related to the query as well as query feedback terms, and then links both the topics and feedback terms to nodes of the knowledge base with corresponding terminological concepts. At least one focal node is selected from the knowledge base based on the topics to determine a conceptual proximity between the focal node and the query feedback nodes. The query feedback terms are ranked based on conceptual proximity to the focal node. A content processing system that identifies themes from a corpus of documents for use in query feedback processing is also disclosed.