I have written a number of blog postings on Compression in DB2 9.1 (just search my blog by putting the word Compression in the search box on the top right corner of this page to find them). Now there are some nice new enhancements to compression in DB2 9.5. In DB2 9.1, in order to build a compression dictionary for a table (or a partition of a table) you had to either perform an offline reorg of
