Return-Path: Delivered-To: apmail-db-derby-dev-archive@www.apache.org Received: (qmail 14889 invoked from network); 9 Dec 2005 05:36:02 -0000 Received: from hermes.apache.org (HELO mail.apache.org) (209.237.227.199) by minotaur.apache.org with SMTP; 9 Dec 2005 05:36:02 -0000 Received: (qmail 54175 invoked by uid 500); 9 Dec 2005 05:35:52 -0000 Delivered-To: apmail-db-derby-dev-archive@db.apache.org Received: (qmail 53944 invoked by uid 500); 9 Dec 2005 05:35:51 -0000 Mailing-List: contact derby-dev-help@db.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: Delivered-To: mailing list derby-dev@db.apache.org Received: (qmail 53935 invoked by uid 99); 9 Dec 2005 05:35:51 -0000 Received: from asf.osuosl.org (HELO asf.osuosl.org) (140.211.166.49) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 08 Dec 2005 21:35:51 -0800 X-ASF-Spam-Status: No, hits=2.8 required=10.0 tests=DNS_FROM_RFC_ABUSE,DNS_FROM_RFC_POST,DNS_FROM_RFC_WHOIS X-Spam-Check-By: apache.org Received-SPF: neutral (asf.osuosl.org: local policy) Received: from [32.97.182.144] (HELO e4.ny.us.ibm.com) (32.97.182.144) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 08 Dec 2005 21:35:50 -0800 Received: from d01relay02.pok.ibm.com (d01relay02.pok.ibm.com [9.56.227.234]) by e4.ny.us.ibm.com (8.12.11/8.12.11) with ESMTP id jB95ZT4j001920 for ; Fri, 9 Dec 2005 00:35:29 -0500 Received: from d01av03.pok.ibm.com (d01av03.pok.ibm.com [9.56.224.217]) by d01relay02.pok.ibm.com (8.12.10/NCO/VERS6.8) with ESMTP id jB95ZT5W125058 for ; Fri, 9 Dec 2005 00:35:30 -0500 Received: from d01av03.pok.ibm.com (loopback [127.0.0.1]) by d01av03.pok.ibm.com (8.12.11/8.13.3) with ESMTP id jB95ZTvj002195 for ; Fri, 9 Dec 2005 00:35:29 -0500 Received: from [127.0.0.1] (sig-9-48-119-226.mts.ibm.com [9.48.119.226]) by d01av03.pok.ibm.com (8.12.11/8.12.11) with ESMTP id jB95ZRie002168 for ; Fri, 9 Dec 2005 00:35:29 -0500 Message-ID: <4399179E.5030402@sbcglobal.net> Date: Thu, 08 Dec 2005 21:35:26 -0800 From: Kathey Marsden User-Agent: Mozilla Thunderbird 0.7.3 (Windows/20040803) X-Accept-Language: en-us, en MIME-Version: 1.0 To: derby-dev@db.apache.org Subject: Re: [PATCH](DERBY-573) Provide support for optimizer overrides in Derby References: <4395D67D.7050809@Sourcery.Org> <4395DE9F.8050503@Sourcery.Org> <4398ABCC.8030606@Sourcery.Org> In-Reply-To: X-Enigmail-Version: 0.85.0.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Virus-Checked: Checked by ClamAV on apache.org X-Spam-Rating: minotaur.apache.org 1.6.2 0/1000/N Mamta Satoor wrote: >Hi Satheesh, > >Thanks for reviewing the patch. > >I think your concern is well founded. A new column in a system table >referenced by metadata.properties would cause a problem in soft upgrade >mode. I am not sure if we have run into this in the past and how we handled >it. > With an older version of Cloudscape a few years ago we had a similar issue where a metadata query referenced a new stored procedure which didn't exist on an older version and to this day we still struggle with that unfortunate event because there are errors recompiling stored prepared statements when reverting to the previous version. After that we changed the Cloudscape code to drop the metadata stored prepared statements whenever the version changed up or down and let them get recreated with the new version. That does not occur with Derby however. My feeling is that it would be safest in the long run to always drop the metadata statements whenever the version changes up or down and let them be recreated with the current version. Too late for existing versions but a safe long term strategy. Just my 2 cents. Kathey