DICTIONARY-BASED ORDER-PRESERVING STRING COMPRESSION FOR MAIN MEMORY COLUMN STORES

摘要

Methods and systems are described that involve usage of dictionaries for compressing a large set of variable-length string values with fixed-length integer keys in column stores. The dictionary supports updates (e.g., inserts of new string values) without changing codes for existing values. Furthermore, a shared-leaves approach is described for indexing such a dictionary that compresses the dictionary itself while offering access paths for encoding and decoding.