From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Thread: 103376,7272aa7508a3d83f X-Google-Attributes: gid103376,public X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news1.google.com!news3.google.com!news.glorb.com!transit.nntp.hccnet.nl!transit1.nntp.hccnet.nl!border2.nntp.ams.giganews.com!nntp.giganews.com!news-in.ntli.net!newsrout1-win.ntli.net!ntli.net!newspeer1-win.ntli.net!newsfe5-win.ntli.net.POSTED!53ab2750!not-for-mail From: "Dr. Adrian Wrigley" Subject: Re: pointer questions User-Agent: Pan/0.14.2 (This is not a psychotic episode. It's a cleansing moment of clarity.) Message-Id: Newsgroups: comp.lang.ada References: <19cfb$4361207d$4995001$19541@ALLTEL.NET> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit Date: Wed, 02 Nov 2005 11:16:44 GMT NNTP-Posting-Host: 80.4.127.115 X-Complaints-To: http://www.ntlworld.com/netreport X-Trace: newsfe5-win.ntli.net 1130930204 80.4.127.115 (Wed, 02 Nov 2005 11:16:44 GMT) NNTP-Posting-Date: Wed, 02 Nov 2005 11:16:44 GMT Organization: ntl Cablemodem News Service Xref: g2news1.google.com comp.lang.ada:6116 Date: 2005-11-02T11:16:44+00:00 List-Id: On Wed, 02 Nov 2005 03:46:41 +0000, Jeffrey R. Carter wrote: > Dr. Adrian Wrigley wrote: > >> This is exactly the situation. The "Things" were about 36 bytes each >> and I changed to having around 20 million pointers to things. >> Single bit errors in pointers had a much more significant effect >> than single bit errors in "Things" (which tended to be ignored >> for various reasons). > > Right. I don't think I'd ever want to consider a continually running program > with 20 million pointers. What did that buy you over the single-pointer version? It was a simple 2-D array of stock data (time/date, ticker). But some tickers had large gaps (no data for long periods). I had been hitting various memory limits. Adding a level of indirection allowed only the valid data to consume memory, keeping the program within those limits. It's still a rather simple architecture, compared to a more traditional SQL database system for this application. But it is *very* fast and (now) very robust. -- Adrian