SNAP_TIME              AVG_VALUE
------------------- ------------
15                       101,683
16                       116,985
17                       118,386
18                       119,463
19                       120,868
20                       121,976
21                       112,906
22                       114,708
23                       116,340

Figure 4.14 - An hourly Signature can show hidden trends

 

For more details on the procedures for plotting Oracle performance data, see the OTN article Perfect Pitch at http://otn.oracle.com/oramag/webcolumns/2003/techarticles/burleson_wait.html.  Open source products such as RRDtool (http://people.ee.ethz.ch/~oetiker/webtools/rrdtool/) can be used to automate the plotting of data from the AWR and ASH.

The same types of reports aggregated by day-of-the week can also be created.  Over long periods of time, almost all Oracle databases will develop distinct signatures that reflect the regular daily processing patterns of the end-user community.