Re: Forcing the use of an index

Hi. Optimizer directive is an available on 7.30. HTH. -- Tsutomu Ogiwara from Tokyo Japan. ICQ#:168106592 >From: "June C. Hunt" <june_c_hunt@hotmail.com> >Reply-To: "June C. Hunt" <june_c_hunt@hotmail.com> >To: informix-list@iiug.org >Subject: Re: Forcing the use of an index >Date: Fri, 9 Jul 2004 10:33:40 -0400 > >David Reed wrote: > > If I have more than one index on a table, how do I force the use of a > > specific index, on a select statment? > >If you are using a version of Informix that supports optimizer directives, >you could use something similar to the following example: > >SELECT {+INDEX(customers cust_index1)} > cust_num, cust_name FROM customers > WHERE cust_active = "Y"; > >The specific syntax of the optimizer directive, shown after the SELECT, is >just one of several possibilities. The two arguments given are table name >and index name. There is also an +AVOID_INDEX optimizer directive that you >can use. > > > Can I do it in the creation of a view? > >Yes. > > > Is there any documentation on this issue that I can look at? > >See the IBM Informix Guide to SQL: Syntax manual. Look up 'Optimizer >Directives'. I've just checked the IBM site and the server where the >documentation is stored is temporarily down. I was going to try to find >out >which versions of Informix allow the optimizer directives (I don't recall - >would have to look it up), but you'll have to determine that for yourself >either by trying it or looking at the proper version of the documentation >once the server comes back up. > >-- >June Hunt > > _________________________________________________________________ STOP MORE SPAM with the new MSN 8 and get 2 months FREE* http://join.msn.com/?page=features/junkmail sending to informix-list