One of our developers used RULE hint widely in our latest project. As a result we had to inspect almost all of them (taking time and $$$) when moving to production. So from now I'm planning to allow RULE then and only then if developer can explain _ALL_ RBO rules :))) (http://download-west.oracle.com/docs/cd/B10501_01/server.920/a96533/rbo.ht= m#38864, http://www.oreilly.de/catalog/orsqltunpr/chapter/) As a result I hope that those who will be able to do that would understand that it is a bad idea. Gints On 4/22/05, Robyn <robyn.sands@xxxxxxxxx> wrote: > I for one will be happy to see the rule based optimizer go. Most of > our developers and dbas add rule hints as a quick fix without taking > the time to actually figure out the problem. Then, they announce > that the query completed 'really fast' in dev and move it to > production, where it may or may not run 'really fast'. Either way, > there is no baseline to work from if we need to continue to tune it. > Plus, the rule hint is likely to exist through the next 3 upgrades, > and no one remembers that it exists, much less knows if it's still > making things 'really fast'. >=20 > As a result, we have lots of legacy queries that need to be > reevaluated and there have been many times when REMOVING the rule hint > in an old query sped things up considerably. -- //www.freelists.org/webpage/oracle-l