Re: change logging

1) "If I use ontape ...". What is the exact usage? If it is ontape -s -L 0 -U dbname, then it should work. If it is anything else, then is won't work. A level 0 archive must be performed in conjunction with changing logging from none to unbuffered (or to buffered for that matter). 2) If you've indexed columns a,b then the Informix documentation (OnLine Dynamic Server Performance Guide) indicates that just using b in the order by clause will *not* use the composite index, as you've experienced. Looks to me that one solution is to create a separate index just on b. Indexing is not trivial, suggest you read as much as you can about it. Also the Optimizer is not trivial, and you should read about it. I like Informix SE a lot because it requires so little administration. Why did you move from SE to IDS (I know there are reasons to do so, I curious about yours - if in fact it was your decision). Benno Eiwen wrote: > 2 questions regarding IDS: > > 1) how can I change a database from no logging to unbuffered logging? When I > use onmonitor it tells me to use ontape. If I use ontape it tells me that > I'm trying an invalid logging change. > > 2) I used to work with Informix SE. I have switched to IDS and it is way > slower. Especially index handling is not clear to me. I have a compound > index on two attributes. If I make a select on the first, order by on the > second it takes forever. If I order on the first and the second it's fast. > How can I tell the optimizer to always use the compound index= > > Your help is very much appreciated. > > Benno