DB2 UDB for z/OS Version 8 Performance Topics - IBM Redbooks

Load table of 20M rows, 10 partitions with 5 NPI or 5 DPSI
tim e
in
seconds
8 0 0
7 0 0
6 0 0
5 0 0
4 0 0
3 0 0
2 0 0
1 0 0
Figure 5-22 Load with 5 NPIs vs. 5 DPSIs
When we compare the single partition load to the previous test case with 1 NPI or 1 DPSI, a
bigger reduction in CPU for 5 DPSIs compared to 5 NPIs is noticed because the index keys
were loaded for all DPSI index physical partitions while keys were inserted into all 5 NPI index
logical partitions during the Build phase. Contention on NPIs is possible.
In case the whole table is loaded the DPSI case shows a slight increase in CPU compared to
the NPI case. In this case 5 NPI data sets vs. 5 DPSI data sets are loaded.
Figure 5-23 presents the measurement results of a reorganization of a partition of a 20 M
rows table with 10 partitions and 1 NPI or 1 DPSI.
Figure 5-23 REORG with 1 NPI vs. 1 DPSI
250 DB2 UDB for z/OS Version 8 Performance Topics
0
5 D P S I
single part
5 N P I
single part
5 D P S I
w h o le
ta b le
5 N P I
w h o le
ta b le
C P U 6 9 2 2 5 7 0 3 6 8 6
Elapsed tim e 4 2 8 7 3 4 0 3 4 2
Reorg a partition of table of 20M rows 10 partitions with 1
NPI and table with 1 DPSI
time
in
seconds
80
70
60
50
40
30
20
10
0
CPU Elapsed time
Table with 1 NPI 51 72
Table with 1
DPSI
25 45