Abstract: In a computer system in which a plurality of hosts is connected through an interconnection network, an apparatus coupled to the interconnection network for allowing the plurality of hosts to share a collection of memory sectors, the memory sectors storing compressed data, is provided. The apparatus includes a network adapter for coupling the apparatus to the interconnection network; a memory for storing the collection of memory sectors; and control logic for managing the memory, the control logic including a memory compressor/decompressor. The memory further includes a directory for translating real addresses of at least one host to an address in the apparatus. A method for managing a number of memory sectors used by each host and a method for translating a real address specified by at least one host into a real address of the apparatus is also provided.

Abstract: In a computer system in which a plurality of hosts is connected through an interconnection network, an apparatus coupled to the interconnection network for allowing the plurality of hosts to share a collection of memory sectors, the memory sectors storing compressed data, is provided. The apparatus includes a network adapter for coupling the apparatus to the interconnection network; a memory for storing the collection of memory sectors; and control logic for managing the memory, the control logic including a memory compressor/decompressor. The memory further includes a directory for translating real addresses of at least one host to an address in the apparatus. A method for managing a number of memory sectors used by each host and a method for translating a real address specified by at least one host into a real address of the apparatus is also provided.

Abstract: A computerized method, system and computer program product for managing an object store is disclosed. An exemplary method includes the the steps of: collecting performance statistics about storage repositories from which an object(s) can be retrieved; retrieving an object from a storage repository, in response to an object reference; determining a reference probability (RFP) for the object; determining and associating a replacement penalty (RPP) with the object wherein the RPP is based on the one or more performance statistics and the RFP; and storing the object and an associated RPP for the object. The storage repositories could be locally attached devices, network sites, and/or remotely attached devices. If there is insufficient space in the object store for a new object, an object(s) can be replaced with the new object based on the associated RPP of the cached objects. Alternatively, the resolution of one or more objects in the object store can be reduced until sufficient space is available.

Abstract: The memory space (often in the form of cache) in a system (e.g., an Internet proxy or web browser) is conserved by saving low resolution versions of data objects when the full resolution version is removed (e.g., due to age, using a least recently used (LRU) replacement policy) in order to create space for new objects. This provides for efficient use of the memory space. In many situations, the low resolution version of the data object is of adequate quality for usage. Further, even when this is not the case, it can be useful to quickly obtain a low resolution version and then with some delay, obtain the full resolution version at the user or application's request. Particular advantageous embodiments of methods, apparatus and article of manufacture implementing the invention are presented.

Abstract: The memory space (often in the form of cache) in a system (e.g., an Internet proxy or web browser) is conserved by saving low resolution versions of data objects when the full resolution version is removed (e.g., due to age, using a least recently used (LRU) replacement policy) in order to create space for new objects. This provides for efficient use of the memory space. In many situations, the low resolution version of the data object is of adequate quality for usage. Further, even when this is not the case, it can be useful to quickly obtain a low resolution version and then with some delay, obtain the full resolution version at the user or application's request. Particular advantageous embodiments of methods, apparatus and article of manufacture implementing the invention are presented.

Abstract: Data representing, for instance, an image is lossily encoded, and a residual of the data is losslessly encoded. The lossily encoded data and the losslessly encoded residual provide a losslessly compressed data representation of the original data. The losslessly compressed data is then organized and stored on a storage system according to one or more criteria selected for the particular losslessly encoded data to be organized. This enables the efficient retrieval and processing of the compressed data, including retrieval of portions of the compressed data.

Abstract: Data representing, for instance, an image is lossily encoded, and a residual of the data is losslessly encoded. The lossily encoded data and the losslessly encoded residual provide a losslessly compressed data representation of the original data. The losslessly compressed data is then organized and stored on a storage system according to one or more criteria selected for the particular losslessly encoded data to be organized. This enables the efficient retrieval and processing of the compressed data, including retrieval of portions of the compressed data.

Abstract: Production and processing of data representing digitized images are disclosed. The disclosure addresses the problem of providing an image which simultaneously represents both high spatial resolution information and low spatial resolution information which pertains to the high spatial resolution information. Images may be produced which represent high spatial resolution information in the form of relative luminance contrasts, and represent low spatial resolution information in the form of color variance. Images representing high spatial resolution information may be altered to represent areas sharing a common trait (low spatial resolution information) by altering image data to make all pixels of those areas a common color, while scaling the luminance of each altered pixel by a uniform factor relative to its luminance in the original representation of the image.

Abstract: An apparatus and method for approximating the data stored in a databases by generating multiple projections and representations from the database such that the OLAP queries for the original database (such as aggregation and histogram operations) may be applied to the approximated version of the database, which can be much smaller than the original databases. Other aspects optimize a mapping, via a mapping (or dimension) table, of non-numeric or numeric attributes to other numeric attributes such that the error incurred on applying queries to the approximated version of the database is minimized. Still further aspects define boundaries of approximations so that the boundaries are preserved when approximated versions of the databases are generated.

Abstract: A system and method for compressing and decompressing data using a plurality of data compression mechanisms. Representative samples of each block of data are tested to select an appropriate one of the data compression mechanisms to apply to the block. The block is then compressed using the selected one of the mechanisms and the compressed block is provided with an identifier of the selected mechanism. For decompression, the identifier is examined to select an appropriate one of the data decompression mechanisms to apply to the block. The block is then decompressed using the selected one of the mechanisms.

Abstract: Minimal random disk write latency is achieved by limiting the number of logical address blocks that can be serviced by a disk to less that the actual number of physically addressable blocks of the system and having a disk controller dynamically map logical data blocks to physical disk blocks in such a fashion that each logical write can take place to any free location, where the free location can be chosen in any track of the current cylinder.

Abstract: A method and apparatus for displaying data on a computer display system. More specifically, with this invention location information of data from an application program is converted to location information for displaying data within a number of contours on a display device. With this invention display data for a logical display area on a first contour is converted to display data for a plurality of contours, where each of the later contours is a logical section of the former contour. More importantly, this conversion is transparent to the application program. The second display data is then displayed on the display device of the computer system.

Abstract: A method and apparatus for compressing a block of data using a shared dictionary. Data to be compressed is divided into subblocks which are each provided to a respective compressor in a plurality of compressors. The compressors cooperatively construct a dynamic compression dictionary and compress the subblocks in parallel using the dictionary. Compressed subblocks output by the compressors are concatenated to form a compressed block.

Abstract: Minimal random disk write latency is achieved by limiting the number of logical address blocks that can be serviced by a disk to less that the actual number of physically addressable blocks of the system and having a disk controller dynamically map logical data blocks to physical disk blocks in such a fashion that each logical write can take place to any free location, where the free location can be chosen in any track of the current cylinder.