Select the actions on this page in order.
This step compares automatic table compression to manual table compression.
CALL ADMIN_CMD
('RUNSTATS ON TABLE CUSTOMER_ADDRESS_WITH_AUTO_COMPRESSION')
SELECT CAST(CAST(NPAGES AS DOUBLE)/256
AS DECIMAL(5,3))
FROM SYSIBM.SYSTABLES
WHERE CREATOR=?SCHEMA?
AND NAME='CUSTOMER_ADDRESS_WITH_AUTO_COMPRESSION'
The second step plots the current table size, the estimated table size, the actual compressed size, and the automatically compressed size on a bar graph.
Since we don't compress the first one to two MB of data inserted into the table it does not compress as much as a full reorganization would compress the data. This is a small table, so one to two megabytes has a significant impact on the overall compression of this table. If the table was gigabytes in size, not compressing the first couple of megabytes is negligable.