Re: Do you ever really get row level locking?

Susan Richards <lnuscsi.sricha01_at_eds.com> wrote:

>All,
> I have been a DBA for several years but am new to Oracle.
>When ever I hear a discussion of the advantages of Oracle "row
>level locking" is always brought up. I am unable to see how
>true row level locking can be achieved. Isn't row level locking
>determined by the INITRANS parameter set in the table. If I
>have an initrans of 1 then only 1 transaction can update rows in
>a page. This is the default. You lose 27 bytes per data block
>for each increase of the initrans parameter. For example if I
>had 100 rows per data block(page) and I wanted true row level
>locking I would lose 2700 bytes of my data block just for
>locking. If I am wrong please enlighten me.
 

>Susan Richards

The INITRANS parameter, which doesn't really have much to do with locking, determines how many simultaneous inserts and updates can be applied to the block. While Oracle7 can handle without error two or more concurrent inserts/updates even if the INITRANS value is one, a better alternative is to have a good understanding of your transaction rates and adjust this value upwards accordingly.

Regarding locking, you can view locked objects via V$LOCK and locking/locked session info via DBA_BLOCKERS and DBA_WAITERS. Rich Woods
Technical Field Support Specialist, Oracle Corporation, USA The above statements and opinions are my own and do not necessarily represent those of Oracle Corporation. Received on Fri Jun 07 1996 - 00:00:00 CEST