Hewlett-packard Company

A9.com, Inc.

Alexander A Stepanov

Robert M English

Daniel Eric Rose

Anil Gangolli

Ryan Jacob Ernst

Paramjit S Oberoi

Chia-Chiang Chao

Andrew J Wilkes

David M Jacobson

Embodiments provide methods and systems for encoding and decoding variable-length data, which may include methods for encoding and decoding search engine posting lists. Embodiments may include different encoding formats including group unary, packed unary, and/or packed binary formats. Some embodiments may utilize single instruction multiple data (SIMD) instructions that may perform a parallel shuffle operation on encoded data as part of the decoding processes. Some embodiments may utilize lookup tables to determine shuffle sequences and/or masks and/or shifts to be utilized in the decoding processes. Some embodiments may utilize hybrid formats.

Encoding of variable-length data with unary formats

Decoding of variable-length data with group formats

An electronic data storage system including a memory, a plurality of magnetic disk units, and a controller. The memory contains an index cross-referencing logical address with physical addresses, an obsolete list and a free list. In response to a 'write ' command, the controller selects a physical address according to which segment can be used the most quickly, appends a tag to the data to be written, and writes the data to the selected segment. Appropriate entries are made in the index and the free list. The system recovers from memory loss by using a checkpoint log and a set of checkpoint segments on the disk that together contain backups of the index and other critical information needed to restore the system. Group indices are used for roll-back groups; operations on data in a group are invisible outside the group until after a 'commit ' command is issued.

High performance multiple-unit electronic data storage system with

An indirectly accessed disk storage device comprises a rotating disk memory coupled to an intelligent disk controller. The intelligent disk controller responds to a request to store a packet of data by determining which storage location of the rotating disk memory are available and by selecting from among the available locations a location that can be accessed in a minimum amount of time relative to access time of any other available location. The intelligent disk controller makes its selection dynamically by monitoring the current position of the recording head of the rotating disk memory and by searching a record of available locations to select an optimal location. The intelligent disk controller then stores the packet of data on the rotating disk memory. By optimizing such data write operations, the indirectly accessed disk storage device also effectively optimizes data read operations. The indirectly accessed disk storage device also improves disk performance by reshuffling data stored on the rotating disk memory according to these policies during idle periods.

Write optimized disk storage device

Growing community of inventors

Palo Alto, CA, United States of America

Alexander A Stepanov