Database Reference
In-Depth Information
With column-oriented storage, only the column 2 parts of the file (highlighted in the fig-
ure) need to be read into memory. In general, column-oriented formats work well when
queries access only a small number of columns in the table. Conversely, row-oriented
formats are appropriate when a large number of columns of a single row are needed for
processing at the same time.
Figure 5-4. Row-oriented versus column-oriented storage
Column-oriented formats need more memory for reading and writing, since they have to
buffer a row split in memory, rather than just a single row. Also, it's not usually possible
