Subject Re: [firebird-support] Re: ORDER BY on large VARCHAR columns
Author unordained
... they can't be chopped up -and- indexing just the first 250 or so chars wouldn't at least help
somewhat? in theory it would reduce by orders of magnitude how many comparisons would be needed,
even if the index couldn't do the entire sort by itself ... or, heck, four or five varchar fields,
using substring? doesn't need to be hierarchical, you've got a set limit on the length ...

(I'm missing the earlier part of the conversation, this has probably been suggested before.)

-Philip

---------- Original Message -----------
From: "robert_difalco" <rdifalco@...>
> >
> > That would certainly make the problem worse. How many records are
> > you retrieving? How long are the keys? Are you sure that the sort
> > is the problem?
> >
>
> Yes, I'm sure about the problem. The VARCHAR is 1024 in length. It
> has qualified names much like a file system, but they cannot be
> chopped up and stored hierarchically. The same query without the
> sort takes a few milliseconds, with the ORDER BY on this field the
> query takes about 2 minutes.
------- End of Original Message -------