Sybase 12.5.1, Руководство пользователя

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Designing playback views
164
Historical Server
• Any playback view can include these data items:
“Timestamp” “Value for Sample”
“Timestamp Datim” “Value for Sample”
“Elapsed Time” “Value for Sample”
“Elapsed Time” “Value for Session”
• The column labeled “Valid for Non-raw?” in Table C-2 indicates which
result data items are allowed in a non-raw playback view. The column
labeled “Conditions for Inclusion” represents conditions under which the
data item is allowed.
• If the “Conditions for Inclusion” column indicates “Full”, the full range of
statistic types valid for that data item is available to the playback view,
regardless of the statistic type used in the input view. Use Table B-3 on
page 148 to determine valid statistic types for each data item.
• If the “Conditions for Inclusion” column indicates “Estimated”, then both
of the following conditions must be true if you want to include the data
item in the playback view:
• The statistic type for the data item must be “Value for Sample” in the
input view, and
• The playback session must be defined to allow estimations. (In the
hs_create_playback_session
command, the allow_estimation
parameter must be
allow
.)
The full range of statistic types valid for the data item is available for the
playback view, regardless of the statistic type used in the input view.
• If the “Conditions for Inclusion” column indicates “Calculated”, then one
of the following conditions must be true if you want to include the data
item in the playback view:
• The data items listed in the column labeled “Other Data Items Needed
for Calculation” exist in the input view. If this is true, Historical
Server calculates values during playback, or
• If the data items required for calculation do not exist in the input view,
Historical Server can estimate values during playback. For this to
happen, the conditions for estimating, described previously, must be
true.
The full range of statistic types valid for the data item is available for the
playback view, regardless of the statistic type used in the input view.