Hi Phil - Thanks for the suggestion. Might that involve possibly changing queries in the web application hitting the database so that it uses the new column, or would the indexing on the new column take care of speeding up the existing queries?
cheers Iain -- --- Phil <[EMAIL PROTECTED]> wrote: > What I've done in the past is to create extra > columns which contain the > reverse of a number/date used previously in an > index. > > So, for instance if it's a simple INT column (A) and > you know the max would > be 9999999 for example, create an extra column and > populate that with > (10000000 - A) and use it as an ASC index. > > Same can be done with dates. > > Not always applicable, but it works and is fairly > easy to implement. > > Phil > > On Tue, May 20, 2008 at 2:20 PM, Bof > <[EMAIL PROTECTED]> wrote: > > > Hi all - > > Is there a good workaround for mysql's lack of > 'DESC' > > functionality when creating an index? > > > > I'm looking at migrating an Oracle RAC database to > > mysql (InnoDB or Cluster - testing both at the > > moment), and the Oracle database uses a lot of > > multi-column indexes with some colums indexed in > > descending order. > > > > If I can't emulate the descending index colums > somehow > > it's likely to seriously impact performance and > > possibly derail the prospect of migration - help! > > > > cheers > > Iain > > -- > > > > > > > > > > > > > > > > > > > > > > -- > > MySQL General Mailing List > > For list archives: http://lists.mysql.com/mysql > > To unsubscribe: > http://lists.mysql.com/[EMAIL PROTECTED] > > > > > > -- > Help build our city at http://free-dc.myminicity.com > ! > -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
