Affiliations: Institute of Computer Science, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw, Poland. [email protected], [email protected]
Correspondence:
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Address for correspondence: Institute of Computer Science, Wroclaw University of Technology,Wybrzeze Wyspianskiego 27, 50-370 Wroclaw, Poland.
Abstract: Solid state disks become the very popular storage devices. Nonetheless, their architecture based on flash memory has some limitations. They suffer from poor random write performance, as the flash memory blocks must be erased before write. Nowadays, among many database models, the column-oriented databases have attracted the attention. In this model, the data from the particular columns of the database table are stored separately in the memory blocks. As a consequence, only such columns are derived from the memory which are necessary for query execution. In this way, I/O number is reduced, what drastically increases the database performance. This paper proposes a new storage method for the column oriented databases on solid state disks. In this method, the data from each column is stored as a separated structure, called Column-Flash tree (CF-tree). The table is always sorted by a particular column (or a set of columns). Due to utilizing fractional cascading and tree-like structure, the efficiency of update and search is obtained. The storage may be adjusted to the altering query pattern and disk characteristics by changing the height of the CF-tree and the capacity of its levels. In contrast to the other models, the approach may be applied to both read and write optimized databases.
Keywords: Solid state disk, data storage, column oriented database
