Re:Locking...

Billy Wheeler wrote: }>From informix-list-owner@rmy.emory.edu Fri Dec 6 06:38:51 1996 }>Received: from rmy.rmy.emory.edu by hobbes.dbintellect.com via ESMTP (940816.SGI.8.6.9/930416.SGI.AUTO) }> for <settler@dbintellect.com> id GAA22578; Fri, 6 Dec 1996 06:38:50 -0700 }>Received: (from ilist@localhost) by rmy.rmy.emory.edu (8.7.1/8.7.1) id IAA01651 for settler@dbintellect.com; Fri, 6 Dec 1996 08:39:19 -0500 (EST) }>Message-Id: <199612060641.IAA24648@west.co.za> }>Comments: Authenticated sender is <billy@pop3.west.co.za> }>From: "Billy Wheeler" <billy@west.co.za> }>Organization: The West Solutions Group }>To: Mik Hobbs <BBT@bbt-ltd.demon.co.uk>, informix-list@rmy.emory.edu }>Date: Fri, 6 Dec 1996 08:27:44 +0200 }>MIME-Version: 1.0 }>Content-type: text/plain; charset=US-ASCII }>Content-transfer-encoding: 7BIT }>Subject: Re: Locking... }>Priority: normal }>X-mailer: Pegasus Mail for Win32 (v2.42a) }>Sender: informix-list-owner@rmy.emory.edu }>Reply-To: "Billy Wheeler" <billy@west.co.za> }>X-Informix-List-To: settler@dbintellect.com }>X-Informix-List-Id: <list.12306> }> }>On 4 Dec 96 at 20:34, Mik Hobbs wrote: }> }>> I've worked on a number of large multi-user informix databases and where }>> there are a number of users inserting / updating data in a table it has }>> always been necessary to have row level locking. }>> }>> It's not correct to state that row level locking only locks the row }>> you're updating, it could also lock adjacent rows where an index is }>> affected. With large volumes you could get -271, -245 & -246 errors. }>> Setting 'lock mode wait' should avoid these errors. }> }>This is only in 5.x, isn't it? I'm sure DSA doesn't lock adjacent }>rows... }>-- }>Ciao, }> }>Billy }> }>I'd be in favour of apathy, but I just couldn't be bothered... }> Don't be too sure. We're running Online DSA 7.20.UC2 on a Silicon Graphics Challenge Server, IRIX 6.2, and we hit the adjacent-row locking problem with lock mode row. Informix Technical support guesses that it's from index-key locking that occurs during inserts. Informix Guide to SQL:Tutorial Version 7.2, page 7-10, discusses these locks on "..a row that does not exist." ------------------------------------------------------------------- Jeff Craig | dbINTELLECT Technologies, Inc. Senior Consultant | Golden, CO | (303) 275-6954 ext. 8008 | email: settler@dbintellect.com | fax: (303) 275-2134 -------------------------------------------------------------------