Re: Informix 5 and 7

Daniel, Don't fall into the trap of over simplifying the differences between 5.x and 7.x, there are many issues worth consideration whenever you plan to move from 5.x to 7.x. This newsgroup have addressed questions about the "differences" for a long period of time. Bottom line is that the 7.x engine is superior to it's predecessor and that it is particularly suitable to SMP platforms. The performance after upgrade is related directly to the attention paid to configuration, tuning and optimisation. Carefull reading of the FM and attendance at one of the 7.x tuning course is definitely the way to go. Regards, Tom Hogarty Pyramid Technology Corp } On Sep 2, 5:41am, Durable MIS wrote: } Subject: Informix 5 and 7 } } Something between Informix 5 and 7 I would like to discuss here. } } } If you use Informix 5 and you want to upgrade to 7 or further version now. } You may discover that the same statements executed in Informix 5 would show } the sqexplain.out as shown: } } Estimated cost : 1 } Estimated # of rows returned: 4 } } However, the sqexplain.out will be display as follows in Informix 7: } } Estimated cost : 128000 } Estimated # of rows returned: 60000 } } } Also, the first one is better than in my experience. } } The difference between them is so large that the performance will be greatly } affected if your tuning is not suited. We should try many many times before } you want to upgrade. } } } } Daniel }-- End of excerpt from Durable MIS