ADAPTIVE DICTIONARY COMPRESSION/DECOMPRESSION FOR COLUMN-STORE DATABASES

摘要

Innovations for adaptive compression and decompression for dictionaries of a column-store database can reduce the amount of memory used for columns of the database, allowing a system to keep column data in memory for more columns, while delays for access operations remain acceptable. For example, dictionary compression variants use different compression techniques and implementation options. Some dictionary compression variants provide more aggressive compression (reduced memory consumption) but result in slower run-time performance. Other dictionary compression variants provide less aggressive compression (higher memory consumption) but support faster run-time performance. As another example, a compression manager can automatically select a dictionary compression variant for a given column in a column-store database. For different dictionary compression variants, the compression manager predicts run-time performance and compressed dictionary size, given the values of the column, and selects one of the dictionary compression variants.

主权项

1. One or more tangible computer-readable media storing computer-executable instructions for causing a computing system programmed thereby to perform a method comprising:
selecting one of multiple available dictionary compression variants to apply to a dictionary for a column of a table in a column-store database; and applying the selected dictionary compression variant to the dictionary.