Abstract: A sorting method used with a distributed database having a plurality of first processors for holding partial records of a database that is divided into a plurality of portions and a host processor for accessing to each of the first processors. The method comprises the steps of: assigning a plurality of sections into which the distribution range of key values of records of the database is partitioned to a plurality of second processors in the first processors, and information for representing storage positions of the records to the second processors to which the sections of the key values, to which the records belong, are assigned; and sorting the plurality of key values, which have been received, in the second processors to produce key tables in which the information for representing the storage positions of the records which has been received is registrated together with the sorted key values, as the sorting result.

Abstract: A method for providing high availability in a production information system is described. The information system consists of a primary and a secondary copy running on a dual machine architecture. A backup database is added to the system which is updated daily from a transaction log. Database maintenance and archive procedures are performed on the data in the backup database relieving the primary and secondary databases of this activity. Database conversion is performed periodically, and the backup database is used to fill in for the primary and secondary databases when they are being converted.

Abstract: Data is transmitted from a mouse to a host computer in accordance with a 3-byte packet protocol. The first byte includes bits indicating the status of first and second buttons on the mouse. The first bit of each byte serves as a sync bit. The sync bit has a value of "1" in the first byte and a value of "0" in each of the second and third bytes. Data representing movement of the mouse in two dimensions is encoded as two 8-bit twos-complement integers which are transmitted as part of the three-byte packet.

Abstract: A file management system has a disk access unit for converting the relative position of a block in a file system into a physical position and accessing data at the position on a disk. The file management system includes a file entity operation unit, a file system manager access unit, and a file management table access unit. The file entity operation unit updates free block data in the file system when creating and deleting a file entity. The file system manager access unit lets the file entity operation unit work with no regard to the medium structure of a file system manager of the file system. The file management table access unit has an entry operation unit for allocating and releasing file management table entries and an entry access unit for referring to and updating the contents of the file management table entries. The entry access unit has a function of extracting soft link data out of any one of the file management table entries.

Abstract: A method and apparatus for reordering complex SQL queries containing joins, outer and full outer joins. The method and apparatus first translates the query into a hypergraph representation. Required sets, conflict sets and preserved sets are then generated for the query hypergraph. Using the required sets, a plurality of plans are enumerated, wherein the plans represent associative re-orderings of relations in the query. SQL operators are selectively assigned to each of the enumerated plans using the conflict sets and/or preserved sets, so that the results from the plans are identical to the original query. A novel Modified General Outer Join (MGOJ) operator may be assigned to the root of a sub-tree, wherein the MGOJ operator is a compensation operator. The operator assignment is performed recursively for the root of each sub-tree in the plan. One of the enumerated plans (generally the most optimal) is then selected for execution.

Abstract: A system for relocating records in a database having a prime region and an overflow region in parallel with a service processing. The system is provided with a database relocation utility which acquires exclusive access to regions of the prime region and the overflow region for which the service processing has not acquired exclusive access. The system saves a predetermined number of records of the prime region and the overflow region into a data save area. Thereafter, the system relocates the records by packing them in one of the prime region and the overflow region.

Abstract: A system for coordinating information transfer, storage and retrieval between and among local processors in a group utilizes a controlled vocabulary of terms which can be modified by various ones of the processors in the group. The controlled vocabulary is utilized in connection with group and local processor functions of storage/retrieval, telecommunications and decision support. The controlled vocabulary can be modified or updated by a remote user by way of a communications channel.

Abstract: A profile is maintained, either in a central profile data base (106) or in a more distributed manner that includes local profile data bases (706). These profile data bases include preference information for particular users, which preference information is utilized by the system to direct various messages from various sources to various destinations for a particular user. By accessing the system through an appropriate input source (708), the user can provide temporary over-ride instructions that cause this preference information to be temporarily altered. When so altered, messages that would ordinarily be directed to a location in accordance with the original entries to the profile data base will be directed instead to a temporary destination (707) as identified by the user. This temporary destination can either be identified in particular at the time of entering the temporary over-ride instruction, or can be pre-identified in an over-ride plan (709).

Abstract: A method, system and program for distributing data to a first node in a parallel database system from a plurality of existing nodes. First, a minimal sufficient number of communication buffers necessary to guarantee that a table scan operation in each of the existing nodes will execute without stopping is determined. Once calculated, the minimal sufficient number of communication buffer is allocated in the memory associated with each of the existing nodes. Thus, data from each of the plurality of existing nodes to the first node can be redistributed without interruption. Unless the redistribution process has a default set of data to be redistributed, which data from which data tables in each of the plurality of existing nodes is to be distributed to the first node must be determined. The first node may either be a new node which must be registered within the parallel database system, or an existing node within an imbalanced parallel database system which has excess capacity.

Abstract: A method is described for finding correlation between a plurality of data having two kinds of numerical attributes and a true-false attribute. The method comprises the steps of: constituting a plane with two numerical attributes, dividing the plane into meshes, and counting the number of data in each mesh (also called a "bucket") and the number of data whose true-false attribute represents true. If each mesh is assumed to be a pixel, such plane can be considered as a plane image in which the number of data corresponds to brilliance, and the number of data whose true-false attribute represents true corresponds to saturation. The method further includes the step of segmenting an admissible image which is convex along an axis of the plane according to a predetermined condition .theta. to find an area with strong correlation. If the segmented area as the admissible image satisfies the above-described condition such as the maximized support rule, the method also presents the area to the user.

Abstract: In a client/server environment, a method and means for reducing the storage requirement in the backup subsystem and further reducing the load on the transmission bandwidth where base files are maintained on the server in a segmented compressed format. When a file is modified on the client, the file is transmitted to the server and compared with the segmented compressed base version of the file utilizing a differencing function but without decompressing the entire base file. A delta file which is the difference between the compressed base file and the modified version of the file is created and stored on a storage medium which is part of the backup subsystem. Alternatively, a copy of frequently accessed base files are maintained on the client in a compressed format. Whenever the client detects that a frequently accessed file has been modified, the modified version of the file is differenced against the base version of that file without decompressing the entire base file and a delta file is generated.

Abstract: A novel B tree data structure is taught and implemented for use in conjunction with a tertiary storage system. The tertiary storage system utilizes three levels of memory hierarchy: primary memory, such as RAM; read-write secondary storage, such as disk memory; and lower speed, and less expensive mass storage, for example a CD-ROM. A novel B tree is utilized to access data stored in two or more types of memory, such as a CD-ROM memory and a disk drive memory, and adapts for the provision of updated data stored on the hard disk which either replaces or supplements data stored on the CD-ROM. The B tree includes, for each data bucket, a pointer for both a CD-ROM and a disk drive location, and are, in certain embodiments, used in conjunction with a bit mask to indicate the presence of valid data in a first one of the memories, such as CD-ROM, and, if desired, a bloom filter associated with data stored in the second memory type, such as a magnetic disk, in order to speed accesses.

Abstract: A database query system includes a query assistant that permits the user to enter only queries that are both syntactically and semantically valid (and that can be processed by an SQL generator to produce semantically valid SQL). Through the use of dialog boxes, a user enters a query in an intermediate English-like language which is easily understood by the user. A query expert system monitors the query as it is being built, and using information about the structure of the database, it prevents the user from building semantically incorrect queries by disallowing choices in the dialog boxes which would create incorrect queries. An SQL generator is also provided which uses a set of transformations and pattern substitutions to convert the intermediate language into a syntactically and semantically correct SQL query. The intermediate language can represent complex SQL queries while at the same time being easy to understand. The intermediate language is also designed to be easily converted into SQL queries.

Abstract: A technique for efficiently joining multiple large tables in a database system with a processor using a small main memory. The technique utilizes a join index and minimizes the number of Input/Output operations while maximizing the use of the small main memory through a buffer allocation process. Three embodiments of the technique are described all of which use the parallel-merge operation. The first technique, slam-join, is for joining two tables and does not require any pre-allocation of buffers to perform the join operation. The second technique, multi-slam-join, is for joining three or more tables and adds the parallel-merge technique to a join technique which partitions memory to be used for an efficient join operation. The third technique, called parallel-join, processes each input table completely independently using the parallel-merge technique. The parallel-merge technique identifies the lowest value from multiple files and orders all the values from lowest to highest.

Abstract: The user of any of a plurality of personal computers linked over an analog or digital network is able to edit a file in one of the personal computers. This one personal computer is a personal computer capable of multi-tasking which effectively permits multi-user access to the file. The host personal computer effectively performs polling of the remote personal computers for input to be added to the file or functions to be performed on the file. In the analog configuration, the personal computers use high-speed modems and data compression/decompression techniques.

Abstract: A method and system for maintaining revision control of a set of objects within a data processing system, wherein the set of objects are linearly interrelated, such that a subsequent object is related to a preceding object. Each object is created, accessed and maintained within a hierarchial promotion structure having a number of levels. A first database is created, which includes data identifying the linear interrelation between objects within the set of objects. The data includes a revision identifier associated with each set of objects. A status indicator is associated with each object within the hierarchial promotion structure, wherein a user may access the set of objects utilizing a revision identifier or hierarchial promotion structure indicator.

Abstract: A reference storage process populates a data structure so that the data structure contains all of the molecular structures and/or rigid substructures in the data base classified according to attributes of tuples. In a preferred embodiment, the tuples are derived from sites (e.g. atomic sites) of the molecular structures and the attributes can be derived from geometric (and other) information related to the tuples. The attributes are used to define indices in the data structure that are associated with invariant vector information (e.g. information about rotatable bond(s) in skewed local coordinate frames created from tuples). These representations are invariant with respect to the rotation and translation of molecular structures and/or the rotation of substructures about attached rotatable bond(s). Accordingly, the invariant vector information is classified in the data structure with the respective tuple attributes in locations determined by the index derived from the respective tuple.

Abstract: The present invention provides an electronic document filing system. The electronic document filing system comprises a document database for storing document, an input unit for controlling the system, a document data generating unit for generating the document data, a layout data generating unit for generating layout data, a display unit for displaying the data generated by the document data generating unit and layout data generating unit, and a control unit for controlling the display unit to send image data of the page being retrieved to the layout data generating unit upon receipt of a retrieval command from the input unit to display the resulting data of a conversion into the layout data, and to send the image data of the specified page to the document data generating unit to display the image data of the specified page in a legible image.

Abstract: In a data set containing displacement-dependent data (e.g., data identified by relative byte address), such as a DB2 log data set, data that is determined to be unneeded or otherwise removable is overwritten with a compressible binary pattern such as a sequence of binary zeros. The resulting substitute data set can be compressed to occupy less storage space and require less time for data recovery.

Abstract: Disclosed herein is a stacked skip list data structure for maintaining select nodes on multiple lists. The data structure includes a primary and a secondary skip list of nodes. Each node in the primary skip list uses at least one forward pointer in a primary array of forward pointers and provides a node level field for storing the level of such node, the level determined by the number of pointers being used. A secondary skip list is stacked on the primary skip list of nodes. It includes a subset (zero or more nodes) occurring on the primary skip list and utilizes zero or more unused forward pointers in the primary array as its forward pointers. Thus, a system agent performing operations on the secondary skip list utilizes the node level in the node level field as an index into the primary array of forward pointers to locate the secondary array of forward pointers.