Abstract: An object storage system provides a storage object to support index structures, logs, and audit trails in WORM storage. The storage object includes a mutable object, an immutable object, or an appendable object. For each storage object, the system maintains an indication of type, such as mutable, immutable, or appendable object type. A mutable object can be arbitrarily modified, an immutable object cannot be modified, and the contents of the appendable object cannot be modified but can be appended with new data. Appended data becomes immutable. The system enables a protection level represented by the object type to be upgraded but not downgraded. Consequently, data committed to be immutable cannot be changed by changing the type of the storage object.

Abstract: A method for reducing data loss and unavailability by integrating multiple levels of a storage hierarchy is provided. The method includes receiving a read request. In addition, the method includes recognizing a data failure in response to the read request. The method further includes locating an alternate source of the data to be read in response to recognizing the data failure. The alternate source includes data cached at devices in the storage hierarchy, data in a backup system, and cumulative changes to the data since the last backup. Moreover, the method includes responding to the read request with data from the alternate source.

Abstract: The invention provides a method for ensuring that data stored on rewritable storage is immutable. The method includes initializing selected user-addressable blocks of storage to a writable state. In addition, the method includes accepting data to be stored in specified user-addressable blocks. Also, the method includes determining if the specified block(s) is writable. Also, the method includes storing the accepted data to the rewritable storage. Moreover, the method includes setting the state of the specified block(s) to non-writable. In one embodiment, the writable/non-writable state associated with each block is encoded and stored in the contents of the corresponding block. In another embodiment, the steps of determining whether the specified block(s) is writable, storing the accepted data to the rewritable storage, and setting the state of the specified block(s) to non-writable, are integrated and indivisible.

Abstract: A correctness verification system receives a query, executes the query using a query logic, and produces a query result. The query result comprises data records that satisfy the query, data verification objects associated with the data records, index segments accessed during the execution of the query, index verification objects associated with the index segments, and the query. The system transfers the query result to a verification system. The verification system verifies correctness of the query result by executing the query using the query logic. The verification system uses the data verification objects to verify integrity of the data objects, uses the index verification objects to verify the integrity of the index segments, and uses the index verification objects and the data verification objects to verify the completeness of the query result.

Abstract: Files are encrypted and stored on a WORM media device along with their encryption keys, the binary values of which are stored as a combination of written and unwritten sectors in a key storage portion of the media. To shred a file, the associated key is destroyed simply by writing into the unwritten sectors that are associated with the key.

Abstract: A method and apparatus for switching data in communication system which comprises of mainly a conversion circuit to receive the source data possessing in a real coding dimension and covert it to converted the data possessing in a tolerable coding dimension; the judgment bits are set in the converted data to designate the data as source data or not. Later on, shifter circuit is used to shift the converted data in certain amount and generates a shifted data; meanwhile, the right side and left side of shifted data are used to start acquiring the real coding dimension to be used respectively as a first data and a second data. Finally, a comparison and selection circuit is used to compare the corresponding judgment bits in the first and the second data and to output an output data, wherein output data is source data with the above-mentioned amount of shift.

Abstract: A method and apparatus for switching data in communication system which comprises of mainly a conversion circuit to receive source data possessing real coding dimension and covert it to converted data possessing tolerable coding dimension; judgment bit is set in the converted data to designate the data as source data or not. Later on, shift circuit is used to shift the converted data in certain amount so as to generate a shifted data; meanwhile, the lowest bit and highest bit of shifted data are used to start acquiring real coding dimension to be used respectively as a first data and a second data, or by changing the pattern of acquiring the first data, then the highest bit minus the real coding dimension bit as the starting bit of the first data, and acquiring the real coding dimension from the side of the lowest bit.

Abstract: A correctness verification system receives a query, executes the query using a query logic, and produces a query result. The query result comprises data records that satisfy the query, data verification objects associated with the data records, index segments accessed during the execution of the query, index verification objects associated with the index segments, and the query. The system transfers the query result to a verification system. The verification system verifies correctness of the query result by executing the query using the query logic. The verification system uses the data verification objects to verify integrity of the data objects, uses the index verification objects to verify the integrity of the index segments, and uses the index verification objects and the data verification objects to verify the completeness of the query result.

Abstract: A method to manage objects in an information lifecycle management system is provided. The method includes determining a score for each of the objects based on a score of at least one feature within respective ones of each of the objects where the score of the at least one feature being associated with a valuation of the at least one feature. The method also includes managing each of the objects based on the score for each of the objects wherein higher scored objects are managed preferentially.

Abstract: Files are encrypted and stored on a WORM media device along with their encryption keys, the binary values of which are stored as a combination of written and unwritten sectors in a key storage portion of the media. To shred a file, the associated key is destroyed simply by writing into the unwritten sectors that are associated with the key.

Abstract: A trustworthy inverted index system processes records to identify features for indexing, generates posting lists corresponding to features in a dictionary, maintains in a storage cache a tail of at least one of the posting lists to minimize random I/Os to the index, determines a desired number of the posting lists based on a desired level of insertion performance, a query performance, or a size of the storage cache, and reads a posting list corresponding to a search feature in a query to identify records that comprise the search feature. The system maps the features in the dictionary to the desired number of posting lists. The system uses a jump pointer to point from one entry to the next in the posting lists based on increasing values of entries in the posting lists.

Abstract: A method to manage data located on networked devices is provided. The method includes replicating objects residing on the devices and collecting information about at least one of the objects or the devices. The method further includes receiving input on desired information governance policies and outcomes and analyzing the replicated objects, collected information and received input to determine an information governance action.

Abstract: Desired transformations such as compression, encryption and/or encoding are applied to data such that the number of duplicate chunks in the transformed data is increased and the chunks are predominantly of a predetermined size. Additionally, the unique and duplicate chunks of transformed data are identified. A variable-sized window is passed over the set of data to generate a working chunk of transformed data that is of the predetermined size. When the working chunk is a duplicate chunk of data, a next group of untransformed data is selected from the set of data, transformed and then evaluated. When the working chunk is not a duplicate chunk of data, a next group of data is selected by sliding the window over the set of data to generate another working chunk that is evaluated.

Abstract: According to the present invention, there is provided a method for reliably storing data in a computer system. The method includes receiving a piece of data to be stored at a storage system. In addition, the method includes writing a first copy of the data to the storage system according to a first data redundancy scheme. Also, the method includes writing a second copy of the data to the storage system according to a second data redundancy scheme. Also, the system includes maintaining metadata of the data written to the storage system according to the second data redundancy scheme. In addition, the method includes copying the data written to the storage system according to the second data redundancy scheme to a backup storage system, wherein the copying is performed in response to a defined condition being met. Moreover, removing the data written to the storage system according to the second data redundancy scheme after it has been copied to the backup storage system.

Abstract: A data chunking system divides data into predominantly fixed-sized chunks such that duplicate data may be identified. The data chunking system may be used to reduce the data storage and save network bandwidth by allowing storage or transmission of primarily unique data chunks. The system may also be used to increase reliability in data storage and network transmission, by allowing an error affecting a data chunk to be repaired with an identified duplicate chunk. The data chunking system chunks data by selecting a chunk of fixed size, then moving a window along the data until a match to existing data is found. As the window moves across the data, unique chunks predominantly of fixed size are formed in the data passed over. Several embodiments provide alternate methods of determining whether a selected chunk matches existing data and methods by which the window is moved through the data.

Abstract: A method for managing data is provided which includes monitoring an activity profile for a given row of a database and determining a target database for a given row based on the activity profile of the given row. The method further includes identifying any row related to the given row and moving the given row and any row related to the given row into the target database while preserving referential integrity.

Abstract: A cost-adaptive cache including the ability to dynamically maximize performance in a caching system by preferentially caching data according to the cost of replacing data. The cost adaptive cache includes a partitioned real cache, wherein data is stored in each of the real cache partitions according to its replacement cost. Also, the cost-adaptive cache includes a partitioned phantom cache to provide a directory of information pertaining to blocks of data which do not qualify for inclusion in the real cache. The partitions in the phantom cache correspond to the partitions in the real cache. Moreover, the cost-adaptive cache maximizes performance in a system by preferentially caching data that is more costly to replace. In one embodiment of the system, the cost of replacing a block of data is estimated by the previous cost incurred to fetch that block of data.

Abstract: A data organization system includes an index that offers fast retrieval of records and that protects records from logical modification. The index includes a balanced tree that grows from the root of the tree down to the leaves and requires no re-balancing. Each level in the tree includes a hash table. The hash table in each level in the tree can use a hash function that is different and independent from the hash function used in any other level in the tree. Alternatively, the hash table in each level in the tree can use a universal hash function. Possible locations of a record in the tree are fixed and determined by a hash function of a key of that record.

Abstract: Stored data can be recovered from a disk array having at least 2n+1 physical disks that are capable of storing n physical disks worth of data when any two disks fail, or when more than two dependent disks fail. Data is stored in data stripes that are divided into n substantially equal-sized strips and are distributed across the n disks. Each data stripe has a corresponding parity strip that is generated by including the data strips in the data stripe only once when the parity strip is generated. The data strips of each data stripe, the copy of each such data strip and the corresponding parity strip are distributed across the disks in such a manner that the data strips of each data stripe, the copy of each such data strip and the corresponding parity strip are each on a respectively different disk of the disk array.

Abstract: A system and method of optimizing storage of common data blocks within a networked storage system comprises receiving a data block to be stored in the networked storage system, analyzing contents of the received data block to determine how many copies of the data block the system is entrusted to store and how many copies of the data block existing within the system, and to identify a location of each copy of the data block within the system, identifying performance and reliability requirements of the system, determining an optimal number of copies of the received data block to store in the system, wherein the determination is made according to a number of copies of the data block the system is entrusted to store together with the identified performance and reliability requirements of the system, and maintaining the optimal number of copies of the received data block within the system.