> I'm looking for a database system for a SCADA system. The major
> probles I think it's on performance because the application it's going
> to poll about 4k variables per second from hardware and has to
> register
> the values on the procces table.
> I heard that PostgreSQL provides a bulk loading mechanism called COPY,
> which takes tab-delimited or CSV input from a file. Where COPY can be
> used instead of hundreds or thousands of INSERTS, it can cut execution
> time.
I think Postgresql can do what you want provide you have the hardware that can
support 4K +
writes/second. However, if you followed the model that PIE uses you could
really relieve the
write load on the database since they only write a 15 second rolling average of
the process values
every minute. A good example of what not to do is how Siemans PCS7 implemented
MSSQL server as
its backend historian. They created a new db every week to hold trended data.
The problem they
faced was that if you requested data that spanned multiple weeks from their
front end they would
sometimes loose weeks of data in the trend. The problem in thier design what
that (for some
reason) they would write data to the wrong database segment.
Regards,
Richard Broersma Jr.
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