Re: SQL Server for Oracle DBAs
Date: Fri, 30 May 2008 05:18:53 +0100
>> 8K cache. Is that true? Boy, I'd really like to use other cache
>> sizes like Oracle can. etc.
I think you mean page size?
Why would you want to use a different page size in SQL Server; by fixing the page size at 8KB the dev team have been able to tune the product to perform the best at that page size.
In SQL Server we physically read or write in chunks of between 512 bytes to 256KBytes and not necessarily in 8KB chunks.
Yes, we have over flow pages when the data spills over, a pointer is stored in the data row out to the over flow page; that can be problematic just like oracle if the data won't fit in 8KB. Realistically out in the real world most table rows are only a couple of KBytes at most so we don't often have this overflow. I note oracle has the same concept which is one reason I can see you'd want to change the page size but realistically it's the only reason I could see that from a SQL Server point of view it may be useful; but frankly - they've tuned the engine to a point it's not that noticeable - index paths etc... get to your data and that's where you'd invest the time in getting it right unless you are daft enough to have a system that constantly table scanned.
Again - it's the attitude I'm talking about that is so dangerous - in SQL Server we don't care and don't require different page sizes but an oracle doctorine says you need to tune your page size to what you are doing - SQL Server is already tuned to 8KB so we can just get on with writing our apps.
I'm starting to understand now why when I come across oracle installs there tends to be two to three times more DBA's then there would be for the equiv SQL Server install.
-- 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]Received on Thu May 29 2008 - 23:18:53 CDT