Entire Playback - Sybase 12.5.1 User Manual

Entire playback

User's Guide
APPENDIX C
Historical Server returns samples whose time intervals correspond to those of
samples in the input sessions. However, samples might be truncated to comply
with the start_time or end_time specified, or if overlaps occur across input
sessions.
If the requested playback start or end times fall in the middle of a sample
interval, Historical Server prorates counted values and performs weighted
averages on percentages and rates. The weights are the number of seconds that
each input sample contributes.
For example, if the playback session start_time is 3 p.m., and an input
recording session has 10-minute samples with one starting at 2:55 p.m., the
first sample in the playback is the one that started at 2:55 p.m., with all values
prorated 50 percent to reflect half a sample.
If playback start_time is later than the input recording session start time,
cumulative session values are played back prorated to reflect the partial
session. For example, if an input recording session started at 1 p.m., but the
playback start_time is 3 p.m., the data item "Device I/O" "Total for Session"
would be a prorated value for I/O since 3 p.m.
This option plays back data for all input recording sessions summarized as a
single sample. For example, seven input recording sessions would result in a
single playback sample. The sample interval is the timespan between the
requested playback start_time and end_time.
The playback view can use statistic types different from those in the recorded
data, and it can include some estimated and calculated data items not in the
original view. It cannot include snapshot data, such as process or lock status
data and current SQL statement data. See Table C-2 on page 165 for a
definitive list of data items that can be converted or added to a playback view.
Choose this option to consolidate recorded data, rolling up details into
overviews of activity over longer time periods.
If the requested playback start or end times fall in the middle of the input
recording session, Historical Server prorates counted values and performs
weighted averages on percentages and rates. The weights are the number of
seconds that each input sample contributes.
Specifications for Defining Playback Views
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