Re: locally managed tablespace & dictionary managed tablespace

"Howard J. Rogers" <howardjr2000_at_yahoo.com.au> wrote in message news:BbQP9.12506$jM5.34484_at_newsfeeds.bigpond.com... <big snip to try and improve my OCR ratio !!>

> However, once I'd shown said colleague that UNIFORM SIZE could take
> arguments like 64K, 256K, 1M and 8M (and once he'd edited the install
script
> to direct each table to the right tablespace) we brought that installation
> down to a mere 94MB. Still a bit bigger than what he'd got in DMT, but
only
> by 10MB.
>

Hi Howard,

I just thinking out loud here so forgive me if this resembles a pile of the steamy stuff...

Just to follow on from the above, if you have a whole stack of very small lookup tables, this could be a good reason for using a small block sized tablespace (9i of course).

By having a 2K block size, you then can have a LMT with a uniform size of 4K. If you have many tables in this category, you can potentially reduce space consumption by an amount.

But also, as you must also have a corresponding 2K buffer cache which can only be used by these objects, by sizing the buffer cache appropriately, you have just invented another KEEP pool (of sorts). All these small, potentially heavily accessed objects can be cached in memory improving performance by ensuring the 2K buffer cache is big enough. I/O could also be more advantages as you also read what's required and little it is too.

Another reason (possibly) why LMT are mmmmmmmmaaaa (big wet kiss kinda sound).

Hope Santa was good to you ;)

Richard Received on Fri Jan 03 2003 - 07:18:56 CST