IBM ESS and IBM DB2 UDB Working Together

Appendix A. Data placement tests 111

Results

As you can see in Figure A-2, the elapsed times for Loads were equivalent for all tests (less

than 3% variance), regardless of placement on the arrays or the method used to ‘carve up’

the arrays.

However, enabling four paths compared to a single path per ESS logical disk improved the

elapsed time of the loads approximately 15%.

Figure A-2 Large versus small logical disks elapsed LOAD times

A tablescan was then run for each test setup using a query similar to the following

(Example A-1):

Example: A-1 Tablescan query

select * from test.rb2a where L_EXTENDEDPRICE < 0;

Again, as shown in Figure A-3, the position ...