Re: How a row is physical stored in Oracle

From: DA Morgan <>
Date: Sun, 07 Sep 2008 11:23:25 -0700
Message-ID: <>

Najm Hashmi wrote:
> Hi All,
> I was just curious to know rows are physically stored for a table in Oracle
> database. Are they stored by Primary Key? If I don't want to store them by
> primary key but some other column, how will I be able to do it.

Depends on the type of table. Default tables in Oracle are heap tables, just like tables in SQL Server and other RDBMS products. You have no control over how or where data is stored.

If you build an IOT (Index Organized Table) then, and only then, is data stored by primary key.

Also available are partitioned tables where you can, again, control storage based on the partitioning template (hash, list, or range) and there are also Sorted Hash Clusters in which, while you don't control how things are stored you can control how the hashes are stored.

Define your terms and explain why you care and in what version. It is all important for getting you a proper answer.

Daniel A. Morgan
Oracle Ace Director & Instructor
University of Washington (replace x with u to respond)
Puget Sound Oracle Users Group
Received on Sun Sep 07 2008 - 13:23:25 CDT

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