| 摘要 |
A table, such as a database table can be partitioned into blocks that are conveniently sized for storage and retrieval. The amount of storage space required and the speed of storing and retrieving blocks is proportional to the size of the blocks. Compressing the blocks leads to less required space and more speed. The columns in a table, and therefore the rows in a transposed block, tend to contain similar data. Compression algorithms can work more efficiently when sequential data items are similar. Therefore, transposing the blocks before compression or compressing them in a column-wise manner leads to better compression. Different compression algorithms can be used for each set of columnar data to yield even better compression.
|
