
46 Unleashing DB2 10 for Linux, UNIX, and Windows
3.3.4 Monitoring compression ratios and optionally performing a
table reorganization
Because the PRODUCT_FORECAST table already has a table-level
compression dictionary, it already contains compressed rows. As the existing
table data is manipulated and new data is inserted into the table, page-level
compression dictionaries are created and dynamically updated as needed.
However, the existing table-level compression dictionary is static; over time, the
table-level compression ratio might gradually decline. Therefore, the DBAs
monitor the compression ratios of the table over time. They can choose ...