Subject Re: [IB-Architect] 'Order By' Issue
Author Dmitry Yemanov

> It is generally (i.e. always) faster to make a sequential pass
> through selected records and sort the results than to bounce
> between the index and the data pages -- a quicksort, even with
> a merge, is faster than a page read. The only time that ordering
> by the index wins is a) the metric is time to first record, or
> b) you aren't planning to look at any but the first few records.


To finilize this thread. You mean that indices are practically ineffective
in sorting, don't you? Hmmm, maybe. I just was sure, that the long process
of pages read through the index is definitely shorter than quick read with
a lot of reads/writes during the sorting, when a record size is very large.
But you're the only expert in the engine internals, so I prefer to trust you.

Best regards,