Re: Delphi/Dynamic Queries slow after Informix Upgrade

In article <6fe3o4$o2b$1@picasso.op.net>, root@candle.pha.pa.us (Bruce Momjian) wrote: >I had posted several weeks ago stating that my Delphi application became >slower after an upgrade to Informix-OnLine Dynamic Server Version >7.24.UC3. Many thanks to those who offered suggestions, like >OPTCOMPIND, but it was already set to zero. > >Here are more details on what is happening. The problem is that since >the upgrade of Informix, prepared queries with parameters from Delphi >are not using indexes, while they did before the upgrade. [snip] >Can anyone shed more light on this? Is it an Informix bug/feature? >Will upgrading to an even newer release fix it? Other people must have >seen this before. I have seen this problem when Delphi talks to Informix SE Engines, but not Online engines. The problem is that Delphi doesn't understand the difference between VARCHAR and CHAR columns - it tells Informix that the columns being indexed are always VARCHARS. This confuses the hell out of Informix SE because it doesn't support VARCHARS. Informix Online must do some kind of sensible conversion. Perhaps 7.24 is not doing this "sensible conversion". Anyway, there is a patch you can make to the source code of Delphi 3 to make it always use CHAR instead of VARCHAR, and I've been assured by some "Director" at Borland in charge of SQL-Links that there will be a more complete fix in Delphi 4. I'll post the patch tomorrow (it's at work, and I'm not) Cheers, Kerry S