--- In firebird-support@yahoogroups.com, Svein Erling Tysvær <svein.
erling.tysvaer@k...> wrote:

> Sorry for answering before properly reading the question...
>
> No, a DESCending index cannot be used with an ASCending ORDER BY.

You

> need two separate indexes if you want to index the field both
> ASCending and DESCending.

> Though note that too many indexes can be as
> bad as too few indexes, create only those that are likely to be
> selective and useful.
>
> Set
>

Indeed. This is the real problem. I display the data (let's say 50,
000) rows in a grid with let's say 10 columns. Now the grid can be
sorted by every column in ASC or DESC order. Imagine how this will
look for 15 columns where I would have 30 indexes that slow down my
INSERTS, UPDATES and are very large because I have 50,000 rows.

I don't get the reason for this unidirectional approach but to me is a
pain in the proverbial arse.

Maybe there is another way of doing this, but the nature of the data
and of the software application forces me to do this.