You can create an expression index on EXTRACT (YEAR FROM DT.DATA) to get
performance improvements in your first expression, but an index on plain
ol' DT.DATA would be more flexible -- it would provide assistance in more
cases than the expression index. The plain ol' column index would speed up
the DT.DATA <= '12/31/2016', but not the EXTRACT... expression.

As always in our business, tradeoffs...

On Fri, Dec 9, 2016 at 12:12 PM Luigi Siciliano [email protected]
[firebird-support] <[email protected]> wrote:

> Il 09/12/2016 15.47, Mark Rotteveel [email protected]
> [firebird-support] ha scritto:
>
>
>
> Could you please put all pertinent information of your question in the
> body, and not only in the subject. It makes questions a lot easier to
> read (especially on mobile devices).
>
> I'm sorry, I rewrite the question:
>
>   what is more performant: "EXTRACT (YEAR FROM DT.DATA) <= 2016" or
> "DT.DATA <= '12/31/2016'"?
>
> I would prepare myself for a table that grows rapidly.
>
> Is the same in FB 2.5.6 or 3.0.1?
>
> Thanks
> --
>
> Luigi Siciliano
> --------------------------
>
> 
>

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