HP System Reporter E-Media Kit, System Reporter Media Kit manual 10.34

3PAR System Reporter User’s Guide	System Reporter 2.8
Table 10-19.Common Performance Columns

Column	Type	Comment
d_rsize15	DOUBLE PRECISION NOT	Difference between rsize15 value from last
	NULL	sample for same object.
wrsize0	DOUBLE PRECISION NOT	Number of writes in IO size bucket number
	NULL	0 (512 bytes).
d_wsize0	DOUBLE PRECISION NOT	Difference between wsize0 value from last
	NULL	sample for the same object.
...	...	...
wsize15	DOUBLE PRECISION NOT	Number of writes in IO size bucket number
	NULL	16 (16MiBytest).
d_wsize15	DOUBLE PRECISION NOT	Difference between wsize15 value from
	NULL	last sample for same object.

Although in principle it was not necessary to store the difference values (d_rcount for example), since these can be derived from previous samples of the same object, in practice having the difference values stored in the data tables greatly simplifies the queries and improves the performance of the queries. As described in the comment for the begin column in Table 10-19, the differences are only valid when the objects have the same begin time.

10.34

The Sample Data and Inventory Tables