Path: dp-news.maxwell.syr.edu!spool.maxwell.syr.edu!drn.maxwell.syr.edu!news.maxwell.syr.edu!postnews.google.com!news3.google.com!border1.nntp.dca.giganews.com!nntp.giganews.com!local01.nntp.dca.giganews.com!nntp.comcast.com!news.comcast.com.POSTED!not-for-mail NNTP-Posting-Date: Fri, 14 Oct 2005 11:44:53 -0500 From: Anne & Lynn Wheeler Newsgroups: comp.databases.theory Subject: Re: Flat Query References: <1129117652.410549.169640@g14g2000cwa.googlegroups.com> <1129170504.862928.236830@f14g2000cwb.googlegroups.com> <1129225535.450679.279390@g44g2000cwa.googlegroups.com> <1129305322.558224.22640@z14g2000cwz.googlegroups.com> Date: Fri, 14 Oct 2005 10:44:52 -0600 Message-ID: Organization: Wheeler&Wheeler User-Agent: Gnus/5.110003 (No Gnus v0.3) Emacs/21.3 (gnu/linux) Cancel-Lock: sha1:lsVAEIaomXtZkh21pVVLvheL2n0= MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Lines: 16 NNTP-Posting-Host: 24.9.100.98 X-Trace: sv3-nNQpeiQh5qwJr3cnygb7ZBnI2E/z8AMMyCLJTgS83Ttp7iRwlnix1pzQfmlWY/w/b2Q653YUL4kZD7b!EY9djSJ718gqqDWe0GJyFCa5ktLD2/P9j7kG7fAPVM28OldbjiVRiyvsmxOrShqWiFcsdKX5MA== X-Complaints-To: abuse@comcast.net X-DMCA-Complaints-To: dmca@comcast.net X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.32 Xref: dp-news.maxwell.syr.edu comp.databases.theory:34031 oh yes, part of the transition to explicit dbms index structures ... basically was when updates & rebuild of a complete sorted flat file became more expensive than the disk space overhead (and associated processing) for explicit indexes that allowed doing incremental updates on the fly (w/o having to rebuild the complete sorted file after each batch of updates). ... oh, and the phone book letter frequency radix search was actually better than the 16-to-5 probe comparison. the phone book was organized using physical 4k records with an avg. of approx. 50 phone records per physical record. the letter frequency radix search could frequently pick the related physical record on the first probe. -- Anne & Lynn Wheeler | http://www.garlic.com/~lynn/