RE: Index Organized tables: Please explain use?

Hannah,
You pretty much summed it up. The db maintains one b-tree structure that = contains both the PK and the "extra" columns for each row. They are useful = for frequent data access through the PK or a prefix of the PK. They take = less storage and provide faster key-based access. To keep the b-tree = densely clustered, you can keep non-key columns in an overflow area. IMH ( = and newbie) O, that seems to be defeating the purpose of using an IOT. = IOTs are not good for DML operations.

Have fun with the "Bible".

Michael Ray
Oracle DBA
TRW, Marshall, IL
217-826-3011 x2438

>>> Hannah.M.Doran_at_sb.com 11/10/00 09:01AM >>>

Good point. I was seeing the IOT as an *ordered/sorted* table. And from = all of
the responses, it seems to be the case. Basically, seems as if its just a = table
with a defined order which occurs on insert, update, or delete (like a = b-tree).
Only, I would think that if the table were LARGE, that there would be some perfomrance impact on arranging it this way. Aren't you basically = re-indexing
with each entry?

I can see using one for lookup tables only. Otherwise, I just dont see = the use
of it (or it may be that I have just not come across a use for it in my = daily
work). Received on Fri Nov 10 2000 - 12:15:29 CST