Re: Help with an Update Statment

The next question is why do you want to build a table that has to be
constantly updated when you can use a VIEW that is always right?

This is fundemental design - beginners 101.

Summary tables are used to assist performance and scalability.

It could often take 20 seconds - 5 hours to work out the aggregations depending on the data set and the complexity of the calculations.

In OLTP data is read many many more times than it is written.

Now imagine your query method took 10 seconds to run for a single user; 100 users running the same query would flat line your CPU and probably push the query time out into minutes - not very scalable.

Unfortunetly because you are classroom based you don't see these real world problems; you are best getting out and doing a beginners programming job for a couple of years to get the necessary fundementals.

--
Tony Rogerson, SQL Server MVP
http://sqlblogcasts.com/blogs/tonyrogerson
[Ramblings from the field from a SQL consultant]
http://sqlserverfaq.com
[UK SQL User Community]

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