Path: csiph.com!usenet.pasdenom.info!weretis.net!feeder4.news.weretis.net!newsreader4.netcologne.de!news.netcologne.de!feeder1.cambriumusenet.nl!feed.tweaknews.nl!194.109.133.86.MISMATCH!newsfeed.xs4all.nl!newsfeed3.news.xs4all.nl!xs4all!post.news.xs4all.nl!not-for-mail Return-Path: X-Original-To: python-list@python.org Delivered-To: python-list@mail.python.org X-Spam-Status: OK 0.004 X-Spam-Evidence: '*H*': 0.99; '*S*': 0.00; 'correct.': 0.07; 'read- only': 0.07; 'newest': 0.09; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'restriction': 0.09; 'sqlite': 0.09; 'sat,': 0.15; 'conclusion:': 0.16; 'concurrency,': 0.16; 'did,': 0.16; 'happily': 0.16; 'received:80.91.229.3': 0.16; 'received:plane.gmane.org': 0.16; 'sqlite3': 0.16; 'url:faq': 0.16; 'url:sqlite': 0.16; 'wrote:': 0.17; 'implementing': 0.17; 'jan': 0.18; '(or': 0.18; 'all,': 0.21; 'precise': 0.22; 'header :In-Reply-To:1': 0.25; 'header:User-Agent:1': 0.26; 'header:X -Complaints-To:1': 0.28; 'all.': 0.28; 'complete,': 0.29; 'locking': 0.29; 'seeks': 0.29; 'connection': 0.30; 'file': 0.32; 'received:com.au': 0.33; 'ryan': 0.33; 'to:addr:python-list': 0.33; 'operations': 0.33; 'version': 0.34; 'open': 0.35; 'received:org': 0.36; 'url:org': 0.36; 'received:au': 0.36; 'xml': 0.37; 'does': 0.37; 'moment': 0.37; 'far': 0.37; 'subject:: ': 0.38; 'description': 0.39; 'to:addr:python.org': 0.39; 'header:Received:5': 0.40; 'your': 0.60; 'first': 0.61; 'close': 0.63; 'respect': 0.63; 'subject:...': 0.63; 'more': 0.63; 'readers': 0.65; '2013': 0.84; 'actually,': 0.84; 'readers.': 0.84; 'dennis': 0.91; 'received:110': 0.96 X-Injected-Via-Gmane: http://gmane.org/ To: python-list@python.org From: Lie Ryan Subject: Re: Vote tallying... Date: Sun, 20 Jan 2013 12:15:02 +1100 References: <50F8906D.9040203@r3dsolutions.com> <50F9518E.3040509@r3dsolutions.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Gmane-NNTP-Posting-Host: 110-175-240-90.static.tpgi.com.au User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130106 Thunderbird/17.0.2 In-Reply-To: X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: General discussion list for the Python programming language List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Newsgroups: comp.lang.python Message-ID: Lines: 23 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1358644515 news.xs4all.nl 6866 [2001:888:2000:d::a6]:43119 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:37101 On 20/01/13 08:22, Dennis Lee Bieber wrote: > On Sat, 19 Jan 2013 22:58:17 +1100, Lie Ryan >> Which is the same restriction as when using XML/JSON. What it means by >> locking the entire database is that an sqlite database can only be >> read/written by a single program at any moment in time. For batch > > Actually, SQLite3 will happily permit multiple readers (or did, the > newest version may have a new locking scheme). However, the first > connection that seeks to write will block as long as open readers are > active, yet will also block /new/ readers. When the open readers close, > the write can complete, and then new readers can enter. Conclusion: > ensure that even read-only operations have a "commit" operation to close > them You're correct. For more precise description of what sqlite can or cannot do with respect to concurrency, see http://www.sqlite.org/faq.html#q5. As far as I know, dbm does not support concurrencies at all, and neither does xml unless you put a lot of efforts into implementing your own file locking and all.