Joe Wilson <[EMAIL PROTECTED]> wrote: > > The old GROUP BY algorithm was extremely efficient whether or > not the GROUP BY terms were indexable or not. >
There were cases where the old algorithm performed very, very poorly. You have found a case where the new algorithm performs poorly, though I think the performance degradation is not nearly as bad as some of the pathological cases with the old algorithm. I'm sorry the new algorithm displeases you. I will make a mental note to try to come up with a better way to do GROUP BY that always works well. Please note that going back to the old algorithm is not an option. Also note that a new algorithm (or going back to the old algorithm) is a large change, requiring weeks of work, and that I have other things that will take priority. So the current algorithm seems likely to be your only option for the foreseeable future. In the meantime, you can work around the problem by implementing the GROUP BY function in your application code. Remove the aggregate functions and GROUP BY clause from your query and just return every row of the intermediate table, then compute the aggregates and grouping yourself. This should be just as fast as the old algorithm in your case. -- D. Richard Hipp <[EMAIL PROTECTED]>
