Re: MS Access / Informix connection is read-only

On Thu, 02 Apr 1998 12:13:25 +0200, Rein Puksand <rpuksand@epbe.ee> wrote: >> >Have you tried Unique Indexes instead of Primary Keys. I think I >> >remember reading somewhere that some ODBC drivers do not recognize the >> >Primary Key attribute. >> > >> > >> >> Thanks for the thought(s). I believe we have the problem solved. It was with >> the keys... Apparently the owner of the keys wasn't the same as the tables and >> the drivers wouldn't recognize the keys. Anyway, they say they are fixing the >> problem and we should be able to reattach the tables and they will be OK. This >> wasn't a problem with the 16-bit Visigenic drivers. >> >> The Unique Indexes would have been a work-around for the problem. When you >> attach the table(s), Access asks you to specify the Unique Index field and if >> you select a field, then the table is also updatable. >> >> Howard > > >Then(if the table have a unique index) scrolling attached( to Informix >7,2) tabels are very slow. >Why? Help? Be aware that Access allways use a key set cursor (one that reads only the field that is defined in Access as the primary key or unique index) to first read the data. Then it uses this to again via another cursor read the actual data to be displayed and only when needed. If you have no index in Informix on the field you spesify in Access you will of course get very slow responce when scrolling as a sequencial search will be done for every row to display. Even if you do have an index may be it isn't used. Have you done update statistics on it? Also read my previous post on how to create primary keys and a corresponding unique index and you will never have this problem. Access will allways find and use the proper primary key. >Rein Puksand Nils Myklebust NM Data AS Norway E-mail: Nils.Myklebust@nmdata.com FAQ at: Primary with ODBC info: http://www.smooth1.demon.co.uk Official site http://www.iiug.org/techinfo/faq/faq_top.html