Address mapping index tuple reconstruction in column-oriented DWMS

摘要

Tuple reconstruction is an essential operation in column-oriented database and has direct impact on the efficiency of query execution. Therefore it is crucial to design a tuple reconstruction method for column store. Focusing on the defects of traditional rowid-based reconstruction method with high cost, this paper proposes a new tuple reconstruction method: address mapping index. This method stores query relevant columns in the leaf blocks of the main index, and establishes the address mapping indices for non-search key columns of the main index. The address set satisfied with the given query conditions can be obtained by combining the address ranges returned by the main index and the address mapping indices during the query execution. The executor gets the corresponding data blocks from the main index according to the address set, which avoids the reconstruction cost and improves the efficiency of multi-column queries. Finally, the experimental results on benchmark data set SSB prove that this method can improve the efficiency of predicted multi-column queries.