Tandem Capacity Model (TCM) Manual

Pick Best CSV Sample
Use the Pick Best CSV Sample option to select the most representative CSV file from all the available
CSV files. When you select Pick Best CSV Sample, the Pick Best CSV Sample dialog box appears.
Select a History file from the available files and click OK. TCM Expert computes the average CPU
seconds for each transaction, assigns a weight to each transaction, and then picks the most
representative sample across all samples.
TCM Expert selects the best sample. Add screen capture for the Pick Best CSV Sample dialog box.
Click Don’t Create to close the dialog box. Click Create to have TCM automatically load this load
sample into a new Performance model.
TCM Expert Parameters
The TCM Expert Parameters option enables you to view or change the global TCM Expert
parameters.
Check History Over Last Field
The Check History Over Last field specifies the exact time period parameters. This field specifies
the time range, which is used in three situations:
• The time range that is checked for transaction cost consistency when Generate Expert is
executed.
• The time range that is checked for transaction cost consistency when Update History with
Selected CSV Samples is executed.
• The time range that is used when the Pick Best Sample option is selected.
The default time period is six months.
Cache Miss Factor
The Cache Miss Factor field specifies the relative CPU cost to the disk process of a cache miss as
compared with a cache hit. The default settings assume that a cache miss costs twice as much as
a cache hit. Only a TCM administrator or superuser can modify this factor.
134 Workload Apportionment Model