Re: Table Fragmentation?

On Thu, 10 Nov 2005 19:10:48 +0000, SG wrote:

> The indexes appear to be ok, we rebuild then as necessary. Once it
> gets slow, we export, drop user/schema with cascade, import data and all is
> back to normal speed. So, what is the first thing I should look for with
> these symptoms? We are using LMT so tablespace fragmentation shouldn't be a
> thought, correct? How about the table? I am new to this so please bare with
> me. What queries can I run against the database to get a baseline for the
> "health" of tables while running well, versus when the system "slows" down?
> Any suggest, insights, advice much appreciated. TIA.

You should buy 2 books: "Optimizing Oracle For Performance" and "Oracle Wait Interface". Continue with export/rebuild/import practice until you finish reading both of them. Also, there is a guy named Tom Kyte who wrote a groundbreaking book named "Effective Oracle By Design". Not being satisfied by the evil done by the first book, he wrote the second one, called "Expert Oracle Database Architecture", which is the only book that I've ever seen to explain thing called write consistency. He does that in a very simple and clear language which anybody can understand. Unfortunately, that book didn't get the rap of the "Effective Oracle" so not many people have read it. Being a compulsive reader, I must confess to have done that. The only thing that I find a little bit under-explained is automatic PGA management. Algorithms used are still a bit unclear and I had to revert to the Benoit paper to fully understand it.

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