Abstract: A method and apparatus for using undo/redo logging to perform asynchronous updates of parity and data pages in a redundant array data storage system is disclosed. The computer-implemented apparatus includes, 1) a redundant array data storage system having a plurality of data pages and a corresponding parity page residing therein, each page of the plurality of data pages and the parity page containing version information indicating a version of content in the page, 2) a memory-resident plurality of data pages corresponding to the plurality of data pages residing in the redundant array data storage system, 3) a data log retaining modification information defining any differences between content of the memory-resident plurality of data pages and content of the plurality of data pages residing in the redundant array data storage system, and 4) control logic for deferring modification of the parity page following modification of one of the plurality of data pages.

Abstract: An apparatus and method for accessing foreign processes in a heterogeneous database environment includes a local database server having heterogeneous services to selectively send foreign operations to the appropriate foreign processes in a controllable manner. A client application sending a statement to the local database server is checked by the local server to determine if the statement includes a reference to a foreign database system. The heterogeneous services selectively outputs a the foreign request to an agent process in communication with the foreign database system via an Application Programming Interface (API), where a foreign database driver corresponding to the foreign database maps the request from the API to the format of the foreign database. The local database server selectively allocates memory space for expected results from the foreign database, and completes execution of the statement upon receiving the expected results from the agent process.

Abstract: A method and apparatus manage shared resources in a multiprocessing computer system. A coordinator process identifies resources to be operated upon by a plurality of worker processes. The coordinator process acquires locks to lock the resources on behalf of the plurality of worker processes. The plurality of worker processes then operate on the resources locked by the coordinator process.

Abstract: A first computer system determines whether a URL contains a first value corresponding to an encapsulating protocol. If the URL contains a value corresponding to an encapsulating protocol, the first computer system determines whether the URL contains an operation protocol key indicating that the URL contains a second value corresponding to an operation protocol. If the URL contains a second value corresponding to an operation protocol, the first computer system selects the operation protocol as the protocol to be employed by the first computer system in issuing a communication to a second computer system. A second computer system determines whether a URL it receives contains a first value corresponding to an operation protocol. If the URL contains a first value corresponding to an operation protocol, the second computer system provides a resource targeted to a first computer system in accordance with an encapsulating protocol.

Abstract: A knowledge base search and retrieval system, which includes factual knowledge base queries and concept knowledge base queries, is disclosed. A knowledge base stores associations among terminology/categories that have a lexical, semantical or usage association. Document theme vectors identify the content of documents through themes as well as through classification of the documents in categories that reflects what the documents are primarily about. The factual knowledge base queries identify, in response to an input query, documents relevant to the input query through expansion of the query terms as well as through expansion of themes. The concept knowledge base query does not identify specific documents in response to a query, but specifies terminology that identifies the potential existence of documents in a particular area.

Abstract: Methods for collecting query workload based statistics within a relational database management system (RDBMS) and for identifying columns for which statistics collection is to be performed. The novel system collects workload statistics that are dependent on multiple columns, rather than merely single columns. Multi-column statistic generation provides more accurate results for columns having correlated data, and therefore leads to better estimated cost analysis by an RDBMS optimizer. In one embodiment, a column duplicity factor is based on an analysis of distinct data rows, e.g., combinations of values within multiple columns, rather than rows of single columns. The novel system also collects separate statistics regarding the presence of null data within the rows of a column group. Separate null data statistics improve the determined result carnality used by the RDBMS optimizer because the cardinality of a relational operation's result is generally determined by the number of input rows with non-null data.

Abstract: A query performance prediction ("QPP") module is provided as part of an applications layer residing on respective user stations operating in conjunction with a centralized host computer system. The QPP module correlates estimated system cost information for a database query provided from a database management system associated with the computer system with statistics compiled from previous queries in order to estimate the system response time. In particular, an estimated CPU time for executing the present query is derived by extrapolating actual CPU times recorded for past queries having the closest estimated costs for accessing the same, or similar, tables and items in the database, using a form of a "nearest neighbor" algorithm to match the present query to either identical or statistically closest past queries.

Abstract: A system, method, and computer readable-medium for performing operations associated with browser requests are provided. The system includes a plurality of dispatchers coupled to a plurality of web listeners. Each of the dispatchers receives from a corresponding web listener browser requests received by the corresponding web listener. The dispatchers are configured to send messages through an inter-machine communication mechanism to cartridge instances. The messages cause the cartridge instances to perform the operations associated with the browser requests. Each cartridge instances includes a cartridge execution engine and a cartridge. The cartridge execution engine handles all inter-machine communication with the dispatchers, and passes the requests to the cartridges by making calls into the application programming interface of the cartridge.

Abstract: A method and apparatus for batch processing of updates to indexes is provided. A plurality of index update records are generated that identify a plurality of index update operations to be made to an index. The plurality of index entry records are sorted and then applied, in an order that corresponds to the sort order, in batches to their respective indexes. As a result of performing batch processing of updates to indexes, the number of disk I/Os will be greatly reduced, freeing database system resources to perform other tasks. The overall efficiency of index maintenance is also improved, as is the recovery of the database system after a failure, resultant from an ordering of the index maintenance operations and a partial ordering of the persistent redo log file.

Abstract: A self monitoring system that identifies optimum summary table(s) for use by a database management system, and that automatically creates or deletes summary tables based on selected summary table recommendations.

Abstract: Methods and apparatus for effective and efficient usage of summary tables in a computer system including a database. In a computer system it is common for a database to include one or more summary tables which have pre-generated aggregations of data from one or more original, detailed database tables. In order to achieve the benefits of summary tables, they must be accessed when appropriate. Thus, information regarding the available summary database tables, including summary bitmaps for all the summary tables, is maintained in the metadata of a computer system. This information is updated whenever a summary table is created. The summary bitmaps are a main key for determining if any summary table is responsive to a user query to the computer system. The summary bitmaps map to corresponding SQL statements, which are generated to access the respective summary tables in the database.

Abstract: A method for selectively caching data in a computer network. Initially, data objects which are anticipated as being accessed only once or seldomly accessed are designated as being exempt from being cached. When a read request is generated, the cache controller reads the requested data object from the cache memory if it currently resides in the cache memory. However, if the requested data object cannot be found in the cache memory, it is read from a mass storage device. Thereupon, the cache controller determines whether the requested data object is to be cached or is exempt from being cached. If the data object is exempt from being cached, it is loaded directly into a local memory and is not stored in the cache. This provides improved cache utilization because only objects that are used multiple times are entered in the cache. Furthermore, processing overhead is minimized by reducing unnecessary cache insertion and purging operations.

Abstract: A method and apparatus for executing queries on a set of data that has been partitioned into a plurality of partitions based on a partitioning key is provided. A query is received that includes a reference to a second key. The second key is not part of the partitioning key but has a predetermined correlation with the partitioning key. This second key is referred to as an overlapping partition key. A subset of the plurality of partitions is selected to be scanned based on the reference to the second key and the predetermined correlation with the partitioning key. The query is then executed by scanning only those partitions of the plurality of partitions that belong to the subset of partitions. The overlapping partition key provides for reduced query execution time even when the partitioning key is not directly involved in the query. Specifically, the overlapping partition key permits a partial table scan in situations that would require a fill table scan with partitioning alone.

Abstract: A method and mechanism for performing a spatial join between two sets of objects employs a two-pass primary filter. The objects are decomposed into variable-sized cells no larger than a predetermined cell size and stored in respective spatial indexes. The spatial indexes include a code for the variable-size cells of the object and a code for the fixed-size supercell of the variable-size cells. The first pass can be implemented as an equijoin filtering operation using the fixed-size cell codes corresponding to the predetermined cell size, and the second pass as a join operation using the variable-size cell codes at smaller cell sizes.

Abstract: A method for preventing multiple pings. An embodiment of the invention detects requests of data blocks entailing pings likely to cause additional pings. The servicing of requests involving a pings likely to cause additional pings is deferred until a service enabling conditions occurs. Another embodiment of the invention detects situations where by further updating a data block before pinging the data block use of resources on the remote node requesting the data block are reduced. The servicing of the request for the data block is deferred until a service enabling conditions occurs.

Abstract: A method for sharing a resource among a plurality of clients is provided. A request is received by a client requesting access to a shared resource. A usage rate is determined for the client. The usage rate of clients are reduced by transmitting a request for a usage reduction to the clients. The request for the usage reduction is initiated independent of a receipt of a message from the clients whose usage rates are being reduced. If a requested usage reduction would reduce a client below a minimum usage rate, then the usage rate of the client is set to the minimum usage rate. The minimum usage rate can be established by the client or by configuration data. The usage rate of a non-real-time client is adjusted based on a uniform rate. If the uniform rate is higher than a maximum usage rate, then the usage rate of a non-real-time client is adjusted to the maximum usage rate. The maximum usage rate can be established by the client or by configuration data.

Abstract: A method, system and computer-readable medium is provided for grouping database objects into logical groupings in order to simplify administrative and other operations that need to be performed by the database server. Such operations can be performed once at the logical group level for a group of related objects, as opposed to at the individual database object level. For increased flexibility, the logical groupings need not dictate the format, schema or location of their members. A hierarchy may be established between the logical groupings, where child groupings inherit some or all of the properties of the parent groupings. A correspondence may be established between some groupings and operating system directories, allowing identifiers associated with the groupings to be used as aliases for the full operating system paths to the corresponding directories.

Abstract: A system and method backs up computer files to backup drives connected to multiple computer systems. Each file in a backup set is allocated to one or more backup subsets for each of the multiple computer systems. The files can be allocated in an even number across each subset, allocated to evenly spread the number of bytes to each subset, or, using the capacity of each of the multiple computer systems, allocated so that each computer system can complete backing up the files allocated to it in approximately the same amount of time. The system can restrict the number of bytes continuously required from a single disk by one of the backup machines from exceeding a threshold limit. Each of the multiple computer systems is then directed to, and the computer systems do, back up files in one or more subsets, which may be allocated to that computer system.

Abstract: Mechanisms and methods for storing, dynamically reconstructing, and navigating a three-dimensional virtual world using a database are disclosed. A virtual world is described in a source text according to the grammar of a modeling language. The source text is read, parsed, and decomposed into a database schema in which characteristics of the world are represented in database tables. In an embodiment, nodes and fields of the world are associated with database queries. When the world is to be displayed, values in the database schema are recomposed into a source text. The database queries are executed against a database, yielding values, in real time based on the current state of the data in the database, for the nodes associated with the queries. Thus, a large virtual world are efficiently displayed and easily modified, and the size, shape, or other aspects of elements of the virtual world can change as data in the database changes.

Abstract: A method and system for performing operations on large objects (LOBs) in a database system are provided. A server receives from a client a command that identifies a row of a table. The table includes a LOB column that contains LOBs. The server responds to the command by sending the client a first set of data from the row. The first set of data includes a locator for a LOB that belongs in the LOB column of the row. The locator includes a LOB identifier that uniquely identifies the LOB and snapshot information that identifies a particular version of the LOB. The server receives from the client a request to perform an operation on the LOB. The request passes the locator for the LOB to a routine provided by the server. The server performs the operation on the particular version of the LOB that is identified in the snapshot information contained in the locator passed to the server by the client.