Re: Q: Update statistics

Paul, I am afraid, your answer is not correct for the latest versions of informix. At least, I could not find any locks imposed by UPDATE STATISTICS in my system (v. 7.22, AIX). Maybe my system is somewhat special, but I truly hope that developers of the UPDATE STATISTICS had realized that locking is excessive: nature of collecting statistics does not require locking. Indeed, one locks the table, scans it, and gets the exact number, which, a second later, becomes wrong, but still is good enough for all practical purposes. Scanning without locking would produce number which, if users are active, is somewhat wrong, but is good enough for all practical purposes. The number is volotile by nature, and final result in both cases is the same, so - why bother to lock? Oleg WF Software wrote: > > In article <6t2986$9th$1@news.xmission.com>, SusanE@fclcis.co.nz (Susan > Elliott (ISG)) wrote: > > > > > Howdy folks, > > > > What is the effect to the users if they are using the system while > > running update statistics is running ? What is, if any is the effect to > > my update statistics ?? > > > > TIA > > Suze > > > > > Depending on the size of the tables involved and the level of stats you > are doing the users will get intermittent locking problems or will be > locked out of the database for a considerable period. If you are using > SPL there is a very good chance you'll hit 211 errors on the sysprocplan > table which will definitely upset the system > > Paul Watson # I don't suffer from > WF Software Ltd. # stress, I'm just > Tel. (+44) 1436 674729 # a carrier > Fax. (+44) 1436 678693 #