Sybase 12.5.1, Руководство пользователя

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CHAPTER 1 Introduction
User’s Guide
5
Playback sessions
Playback sessions let you retrieve the data gathered during one or more
recording sessions. You can play back data in two forms:
• Playback to a client – the results of the playback are sent to the user, who
can view the results on the terminal or redirect them to a file.
• Playback to a file – the results of the playback are stored in a file. The
resulting files are essentially a new recording session. You can use these
files as input to yet another playback session, or as input to the
bcp
utility
to populate Adaptive Server tables, or any other way that you would use
recording session files.
The following attributes define a playback session:
• Input recording sessions – the input to a playback session is one or more
recording sessions.
• Views, start time, and end time – these attributes define the data from the
input recording sessions that you want to include in the playback session.
• Summarization level – you can specify raw playback, which shows you
exactly what was recorded, or you can specify various summarization
levels.
To create a playback session, use the following sequence of commands from
the Historical Server command interface:
•
hs_create_playback_session
•
hs_create_playback_view
•
hs_initiate_playback
•
hs_playback_sample
(used only for playback to a client)
•
hs_terminate_playback
Views
A recording session view defines the performance data you want Historical
Server to gather. A playback session view defines which performance data
from a recording session view you want Historical Server to play back.
A view consists of a view name and one or more data items. Each data has a
statistic type associated with it. See “Data items and statistic types” on page 6
for more information.