Abstract: A method for determining k nearest-neighbors to a query point in a database in which an ordering is defined for a data set P of a database, the ordering being based on l one-dimensional codes C.sub.1, . . . , C.sub.1. A single relation R is created in which R has the attributes of index-id, point-id and value. An entry (j,i,C.sub..epsilon.j (p.sub.i)) is included in relation R for each data point p.sub.i .EPSILON.P, where index-id equals j, point-id equals i, and value equals C.sub..epsilon.j (p.sub.i). A B-tree index is created based on a combination of the index-id attribute and the value attribute. A query point is received and a relation Q is created for the query point having the attributes of index-id and value. One tuple is generated in the relation Q for each j, j=1, . . . , l, where index-id equals j and value equals C.sub..epsilon.j (q). A distance d is selected. The index-id attribute for the relation R of each data point p.sub.

Abstract: In a computer application having a counter for setting first and second counter values in respect of first and second objects. The counter has a range of n possible values and being incremented or decremented in accordance with update criterion. The application taking an action according to whether the first counter value is larger or equal to the second counter value. A method for handling a courter overflow event whereby the counter is incremented beyond said range by executing the steps of: compacting the first and second counter values to m values (m<n) so as to constitute first and second compacted counter values, such that if the first counter value id larger than or equal to the second counter value then the compacted first value is not smaller than the compacted second value, and setting the counter to a value from among n-m values within the specified range.

Abstract: A system for garbage collection of memory objects in a memory heap. The system includes memory heap that is partitioned into respective old and young areas. The old area is partitioned into cars and is further associated with card markings and remembered sets data structures. The card markings include for each card, a card time stamp that represents the time that the card was updated. The car includes, for each car, a car time entry stamp that represents the time the remembered set of the car was updated. The system further includes a processor communicating with the memory, and being capable of identifying all cards that were updated later than the remembered set of a selected car. In response to the event, it performs identifying change in pointers that refer from the card to a memory object in the selected car and in response to identified change in pointers, updating the remembered set of the car with the identified pointers.

Abstract: In a distributed computing system in which replicas of a document are separately stored and revised, the document containing data arranged in a number of fields, a method for replicating data contained in a revised document replica to the other of the replicas by replicating only the field or fields which have been revised since an earlier replication. The method includes the steps of dynamically maintaining a two byte document sequence number for each of the document replicas representing the number of revisions made to the replicas, and dynamically maintaining a one byte field sequence number for each of the fields in the replicas. The field sequence numbers for revised fields are set equal to the lower byte of the current document sequence number.

Abstract: A programmable interpreter for creating, interpreting, and executing a programming language. The present invention is a virtual processor that eliminates interpretation of pseudo code typical of common interpretive engines. The preferred embodiment of the present invention includes a computer system comprising a bus communicating information, a processor, and a random access memory for storing information and instructions for the processor. The processing logic of the preferred embodiment is operably disposed within the random access memory and executed by the processor of the computer system. A command stream, comprising a command identifier or function name in combination with a string of arguments, is a typical input for the processing logic of the present invention. Upon activation of the processing logic of the present invention, a parser is executed to manipulate the input command stream and produce an execution stream with a processing component identifier corresponding to the specified command.

Abstract: A method and data processing system are disclosed for translating an ad-hoc user input string into Structured Query Language. A user input string is parsed placing joiner objects and left parentheses into a temporary pushdown stack and placing query clause objects into a postfix queue. After encountering a query clause object or a right parenthesis, the next item in the pushdown stack is placed in the postfix queue if it is a joiner object. Once the input string is parsed, objects in the postfix queue are placed into a second temporary pushdown stack and also used to form common table expressions using adjacent items in the second pushdown stack. Finally, an SQL SELECT statement is formed using a JOIN on the ids returned by the common table expressions.

Abstract: Every node in a multi-node parallel database system maintains a logical clock for generating timestamps. The logical clocks are synchronized by attaching a current timestamp to every message that is sent by a node. When a node receives an incoming timestamp that is greater than the value indicated by the associated logical clock, it sets the associated logical clock forward to at least the value of the timestamp. Each node continually sends and receives a message including a timestamp at least once in a prescribed period of time. Moreover, each node maintains a high watermark that represents a time greater or equal to the highest time of any logical clock in the multi-node parallel database system.

Abstract: A method and apparatus for providing dynamically controlling access to files in a client/server system. A client wanting access to a file first requests a token from an object server. The object server generates the token as a function of the file name and ephemeral information and provides the token to both the client and the file system. Upon receiving the token from the object server, the client presents an access request to the file system, using the token rather than the file name as an identifier. The file system compares the received identifier with the file names in the specified directory as well as with a list of valid tokens that it maintains. If the identifier corresponds to a valid token for a file in the directory, the access request is granted. Otherwise, the access request is denied. The procedure is transparent to the client, which uses the token in the same manner as it would use a regular file name.

Abstract: A system, method and computer program are provided in an installable file system (IFS) for a network server for enabling access to and distribution of Audio CD information over a client server network by creating a virtual directory of computer audio files from Table of Contents information read in raw sector mode from an audio CD in a CD-ROM drive, which virtual audio files appear to the server's operating system as normal files stored on a convention file system.

Abstract: A method and system for creating and maintaining a journal of transactions directed to a configuration database is disclosed. A multi-threaded journaling method logs transactions in a configuration database by first receiving a database transaction, the transaction being either a single modification, e.g. insertion, deletion, update, or a series of modifications directed to the configuration database. An initial entry is inserted into a journal file where the initial entry includes a transaction identifier or handle that corresponds to the database transaction. Subsequent entries are inserted into the journal file corresponding to the specific updates of the transaction, the subsequent entry containing the transaction identifier and actual transaction data relating to the specific update. The journaling mechanism then determines whether each of the specific updates to the configuration database has been successfully completed.

Abstract: A method, apparatus, and article of manufacture for a computer implemented two-level caching system. A statement is executed in a computer. The statement is executed by the computer to manipulate data in a database stored on a data storage device connected to the computer. Initially, a first statement is prepared to create an executable structure for executing the first statement from an application. Then, the executable structure is stored in an application-level cache associated with the application. A second statement is received for execution from the application. It is determined that the second statement can be executed using the stored executable structure for the first statement. Next, the second statement is executed using the stored executable structure.

Abstract: Query evaluation is optimized using parallel optimization techniques to make repartitioning more efficient. Efficiency is improved by recognizing the possible partitioning requirements for achieving parallelism for a query operation, and by recognizing when the partitioning property of data satisfies the partitioning requirements of a query operation. A data base management system in accordance with the invention uses parallel query processing techniques to optimize data repartitioning, or to avoid it altogether.

Abstract: Methods and systems are provided for providing locking in a system. The resource objects of the system can be persistent, and thus provide finer granularity locking by allowing shared resource objects to be dynamically allocated and de-allocated. The persistent nature of the resource objects allows for the dynamic allocation and de-allocation of the resource objects, while guarding against the abnormal release of resource locks that result in the possibility of inconsistent data. If abnormal release occurs, the affected resource object(s) are marked to indicate that they are in a "dubious" state. The dubious resource objects are not dynamically de-allocated, but are instead allowed to persist until corrective or validation actions are taken. If the locks are validly released, then the resource objects can be safely de-allocated.

Abstract: A mapping between an object model and a relational database is generated to facilitate access to the relational database. The object model can be created from database schema or database schema can be created from the object model. Further, the mapping can be automatically generated. The Database schema, object model and mapping are employed to provide interface objects that are utilized by a runtime engine to facilitate access to the relational database by object oriented software applications.

Abstract: A data storage subsystem employs managed files, each comprising one or an aggregation of multiple individual, constituent user files, to reduce file management overhead costs. After receiving user files from a client station, the subsystem creates a contiguous managed file by aggregating selected ones of the received user files according to certain predetermined criteria. Managed file creation and use are transparent to the client stations. To aid in file management, the subsystem provides a mapping table that lists, for each user file, a corresponding location of that user file within a managed file. With this hardware and table structure, the system conducts file management with reduced overhead. For example, internal data management operations include an improved copy operation where a managed file is copied as a contiguous unit between first and second locations in the data storage subsystem.

Abstract: By collecting or creating information written in a specific descriptive system, making a real model defining the concept handled in the organization activity, analyzing the domain for defining the words by stratifying each concept on the model of each basic concept of at least person, organization, article, document, meeting and event for composing the organization activity, analyzing the sentence pattern for defining the context by stratifying on the model of the concept of action, and by fitting and integrating the word defined by domain analysis and sentence pattern analysis into the context, a logical model corresponding to the real model is created. Thereby an organization activity database, in which information about various events necessary for organization activity and information of achievements resulting organization activity are integrated, is constructed.

Abstract: In a client/server computing system, a method and apparatus for efficiently storing entries in a log file during disconnected client operations. An encoder utilizes a log file and a write file table for logging the write operations performed by the client during disconnected operations. The logging method employed by the encoding module logs in the log file only writes associated for different files. The encoding module tracks the status of the entries in the log file with a write file table containing the most recent sequence number associated with a file entry of the log file. Upon reconnection of the client to the server, a decoding module replays the events in the correct chronological order by transferring the file data modified during the period of disconnection in the order dictated by the write file table. A deferred write list is accessed by the decoding module for temporary storage any write operations whose replay should be delayed to preserve the relative order of events.

Abstract: Fileserver buffers are managed so as to improve the hit ratio for read accesses to the fileserver by clients by grouping related files into filesets, collecting fileserver access operation (i.e., read and write) statistics for each of the filesets, classifying the filesets into a plurality of fileset categories having similar collected access operation statistics and then implementing different fileserver buffer management policies for the blocks (or pages) from each of the different fileset categories. The buffer management policy applied to each of these categories is designed to create a generally higher preference for retaining blocks (or pages) of files in the fileserver buffers having a generally higher read to write ratio.

Abstract: A method and apparatus for interfacing with a stateless NFS (Network File System) server. A pseudo-open state is created for a file when a request from a network client for accessing the file is received in a network server. The term pseudo-open data relates to a set of data that is kept in a network server. The pseudo-open describes the state of a file being currently accessed via an NFS server in the network server. The pseudo-open data differs from normal file state data in that it can be created or recreated at will, thus preserving the stateless functionality of the NFS server. Thus, if a request is received at any time and there is no pseudo-open state established for the file, the pseudo-open state will be established or reestablished at that time. If, on the other hand, a request is received for which a pseudo-open state already exists, the overhead of creating the pseudo-open state is avoided, and the existing data is used. The pseudo-open state is stored in a file-system data structure called VNODE.

Abstract: A method, apparatus, and article of manufacture for accessing non-object-oriented data using object-oriented techniques. A computerized system in accordance with the principles of the present invention includes a "bridge" that interfaces between an application program and a non-object-oriented database management system to materialize data retrieved from the non-object-oriented database management system as objects that can be manipulated by the application program. The bridge includes a "collection of object collections" for modeling hierarchical structures, a datastore collection made up of one or more datastore persistent objects, and an instance manager. A datastore class definition tool generates class definitions for datastore persistent objects that encapsulate or wrapper the data retrieved from the non-object-oriented database management system.