Re: Locklevel

From: Sybrand Bakker <postbus_at_sybrandb.demon.nl>
Date: Tue, 27 Aug 2002 14:59:33 +0200
Message-ID: <qotmmukjit9nacl0mfn35rmk9nnmd26p1h@4ax.com>

On Tue, 27 Aug 2002 14:08:43 +0200, Dirk Scheer <dirk.scheer_at_stadt-mh.de> wrote:

>Hello out there,
>
>can anybody tell me, what the default lock level of an Oracle database is?
>If I do a
>
>select ... from ... for update;
>
>Are there only the records found locked?
>Is it possible to lock a complete block?
>
>If it sounds a little bit strange to you: I'm coming from Informix. This
>database distinguishes between row level and page level locking. Are there
>comparable mechanism in Oracle?
>
>Thx in advance...
>Dirk

Default is row locking. There are exclusive locks and share locks (share locks mean the record can still be read) There is also table level locking, with exclusive and share locks Page level locking does not exist.
Also in Oracle readers do not block writers

The Concepts Manual at http://tahiti.oracle.com in discusses this in detail, as the Expert one on one book by Thomas Kyte also does.

Hth

Sybrand Bakker, Senior Oracle DBA

To reply remove -verwijderdit from my e-mail address Received on Tue Aug 27 2002 - 07:59:33 CDT