Re: DSA 7.22.UC1/HPUX 10.20

In article <332C5837.EB5@netcomuk.co.uk>, Ian Goddard <igoddard@netcomuk.co.uk> writes >David Coburn wrote: >> >> Hi. I have an odd problem here. DSA 7.22.UC1 is demonstrably >> slower on my HP 9000/K420. I have an EMC disk array with 56Gb >> attached, 4 cpu's and 1Gig real memory. Disk I/O screems >> during insert/update, performance is beyond reproach during >> index builds, etc. The problem is that queries are slow. This >> wouldn't be much of a problem, except that we're replacing an >> old Unisys running 7.10.UC5 that should be 5-7 times *slower* >> than the HP, based on the usual metrics. Queries, though, that >> take sometimes hours longer to complete. >> >> We've checked all the usual suspects. Indexes are in place, > >Agreed - it hould run a bit quick - but your list of usual suspects >didn't include the results of setting sqexplain on. > >Ian Check in your onconfig file that OPTCOMPIND is set to 0 rather than 2. The default for OPTCOMPIND is 2 in ~v7.12 and above. With OPTCOMPIND set 2 you would get Dynamic Hash Joins used rather than indexes which accounts for the memory usage + cpu utilisation. Another site with the same problem....perhaps we ought to get a petition together to get Informix to change the default??? If so, e-mail me and I'll put one together - we hit this problem twice, once with 7.12 and once again when we upgraded that to 7.13. Yes that's right WHEN WE INSTALLED 7.13 IT MODIFIED OPTCOMPIND TO 2 IN OUR ONCONFIG FILE!!!! -- David Williams