September 2010
Intermediate to advanced
1704 pages
111h 8m
English
Row-level compression isn’t true data compression. Instead, space savings are achieved by using a more efficient storage format for fixed-length data to use the minimum amount of space required. For example, the int data type uses 4 bytes of storage regardless of the value stored, even NULL. However, only a single byte is required to store a value of 100. Row-level compression allows fixed-length values to use only the amount of storage space required.
Row-level compression saves space and reduces I/O by
• Reducing the amount of metadata required to store data rows
• Storing fixed-length numeric data types as if they were variable-length data types, using only as many bytes as necessary to store the actual value
• Storing ...