RE-ALIGNING A COMPRESSED DATA ARRAY

摘要

Two-dimensional compressed data sets can be re-aligned while preserving compression of the data. A set of one or more shifts and a corresponding set of one or more first dimension indices into a two-dimensional compressed data set for re-aligning the two-dimensional compressed data set are determined. Impact of re-aligning upon each vector in the second dimension of the two-dimensional compressed data set is determined while the two-dimensional compressed data set remains compressed. New compressed vectors are created in the second dimension resulting from re-aligning. Compression information is modified for each of the original vectors of the two-dimensional compressed data set that remain after re-aligning based, at least in part, on the new compressed vectors. A re-aligned version of the two-dimensional compressed data set is created with the new compressed vectors, and the remaining original vectors with their modified compression information.

主权项

1. A method comprising:
determining a maximum shift value of a set of one or more shift values for re-aligning a two-dimensional data set, wherein each of the set of one or more shift values indicates shifts at a specified index into a first dimension of the two-dimensional data set, wherein the two-dimensional data set is compressed along the first dimension; for each second dimension vector of the two-dimensional data set,
determining whether shifting for each of the set of one or more shift values at the specified index into the first dimension of the second dimension vector results in a different vector than either a previously created vector or the second dimension vector;if shifting results in the different vector, adding the different vector to a re-aligned array;if shifting does not result in the different vector, incorporating a compressed form of the second dimension vector into the re-aligned data set.