Mark Simms
marksimms at verizon.net
Mon May 14 16:58:09 CDT 2012
Given how brittle the creation process of Calculated fields is, you would have thought that indexing would be one of the features. > -----Original Message----- > From: accessd-bounces at databaseadvisors.com [mailto:accessd- > bounces at databaseadvisors.com] On Behalf Of Stuart McLachlan > Sent: Monday, May 14, 2012 4:57 PM > To: Access Developers discussion and problem solving > Subject: Re: [AccessD] AC2010-a pioneer with more arrows in the back... > > I didn't notice until Asger pointed it out that you can't index a > calculated field. That removes > one of the big reasons for using them. Guess I'll stick with queries. > > -- > Stuart > > On 14 May 2012 at 17:18, Asger Blond wrote: > > > Yes, and I didn't find any noticeable difference. Having the > calculated > > values persisted in the table would both benefit and hurt performance > > - 1) benefit since no calculation is needed for the query engine, but > > 2) hurt since the query engine has to traverse much more data pages > > (remember, that the calculated field makes the table much larger). > > > > /Asger > > > > -----Oprindelig meddelelse----- > > Fra: accessd-bounces at databaseadvisors.com [mailto:accessd- > bounces at databaseadvisors.com] På vegne af Mark Simms > > Sendt: 14. maj 2012 16:28 > > Til: 'Access Developers discussion and problem solving' > > Emne: Re: [AccessD] AC2010-a pioneer with more arrows in the back... > > > > Thanks for that.....I've always been paranoid about updateable > > queries...seeing so many that should have been updateable but were > not. > > In your testing of Calculated columns, did you look at retrieval > speed ? > > Query with Calculated field vs. Table with Computed column with a > where clause > > using that field/column ? > > > > > > > > -- > > AccessD mailing list > > AccessD at databaseadvisors.com > > http://databaseadvisors.com/mailman/listinfo/accessd > > Website: http://www.databaseadvisors.com > > > > > > -- > > AccessD mailing list > > AccessD at databaseadvisors.com > > http://databaseadvisors.com/mailman/listinfo/accessd > > Website: http://www.databaseadvisors.com > > > > -- > AccessD mailing list > AccessD at databaseadvisors.com > http://databaseadvisors.com/mailman/listinfo/accessd > Website: http://www.databaseadvisors.com