Experimental Physics and
Industrial Control System

"Kasemir, Kay" <[email protected]> · Tue, 28 Sep 2010 20:30:15 -0400

Hi:

>How do the various archiving systems compare if one needs to see all the
>changes for 50,000 channels or more over a relatively short period of time?

The Channel Archiver, be it the one based on binary files or on an RDB, has no tools to help you with that.
One problem might also be that you probably don't exactly know what you're looking for.
I assume a scenario is that something happened, and now you want to figure out why, grasping at straws in the form of PVs that changed at some time.

For the file based Channel Archiver, you would have to create such a tool in C++, and I think it would be reasonably hard.

With the RDB-based Channel Archiver, most people who know something about databases could use basic SQL to look around, for example:
How many PVs did change?
->  SELECT count(*) FROM sample WHERE smpl_time BETWEEN ? AND ?

Then you could get their names, and once you think you have those 10 names that you're interested in, you can drag/drop the names from for example SQL Explorer where you try those SQL statements iinto the CSS Data Browser to view the data in there.

-Kay

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System