On Sat, Dec 10, 2016 at 12:37 AM, Louis Kleiman lklei...@sstms.com [firebird-support] <firebird-support@yahoogroups.com> wrote:
> > > 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 luigi...@tiscalinet.it > [firebird-support] <firebird-support@yahoogroups.com> wrote: > >> Il 09/12/2016 15.47, Mark Rotteveel m...@lawinegevaar.nl >> [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'"? >> > DT.DATA <= '31.12.2016' /* date format dd.mm.yyyy */ could be ignoring the hours part ie from '31.12.2016, 00:00:00.001' to '31.12.2016, 23:59:59.999' better use DT.DATA < '1.1.2017' > 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 >> -------------------------- >> >> > -- Regards, Lt Col (Retd) Rajiv D.S. Chauhan in.linkedin.com/in/ltcolrdschauhan
