Re: Index organized table

From: buu <aha_at_a.com>
Date: Tue, 17 Jun 2008 19:15:09 +0200
Message-ID: <1213722917.115762@news.vmware.amis.hr>


> Index and data separation. Richard wrote some excellent articles about
> this myth - err - concept:
>
> http://richardfoote.wordpress.com/2008/04/16/separate-indexes-from-tables-some-thoughts-part-i-everything-in-its-right-place/
>
> From a glance at this I'd say that you might need less space with an IOT.
> But space is not everything. Btw, are you sure that you'll never do
> lookups based on PAGEURL?

I'm sure that I will not need an pageUrl as an any kind of key.

> I tend to be conservative about these things that's why I would leave it
> at the default unless there are reasons to change it. I'd probably create
> both versions and fire a defined load (sequence of insert, select etc.
> statements) against both and measure performance as well as final size of
> both tables and indexes. If you are just concerned with the size you
> could just copy your current contents into a second table and look at the
> sizes - although that will yield slightly skewed results (because of the
> missing deletions and updates which might leave some holes).
>
> If your volume is going to be large then partitioning would also be a
> technique to think about but in your case hash partitioning seems the only
> realistic option and then you have to carefully choose the partitioning
> key so you can benefit from pruning for PK and SITEID accesses. Ideally
> you would want to have partition local indexes only.
>
> Kind regards
>
> robert

tnx a lot.
I tried to create a separate copy of it and to make a load to see cpu/time needed for that.
But, next problem was that I cannot find stats/size data in my Toad for that (currently Oracle 10.2 XE with an Toad 8.5.1). I can see this data for all other tables, but not for IOT.
Also, there are no data about IOT in tablespace info, and not in user_tables (there are info, some are null).

do you know anything about that?

tnx... Dario Received on Tue Jun 17 2008 - 12:15:09 CDT

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