Обсуждение: Re: [SQL] How to Make Case InSensitive???

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Re: [SQL] How to Make Case InSensitive???

От
Mirek Budzanowski
Дата:
> > I working with a table of about 70'000 records and I made 2 tests about
> > the optimisation of ~* :
> >
> > With ~* :

> > real 11.52 *
> > user 0.02
> > sys 0.01
> >
> > With upper(...) and like upper(%...%)
> > --------------------------------------

> > real 4.44 *
> > user 0.03
> > sys 0.00
> >
> > Relsult: it seem to be 2.6 time more optimised to use upper(...) like
> > upper('%...%') ???

> This is interesting.  Does anyone have an idea why this is happening?

In my opinion the reason why regular expresion matching is sloer is
obvious. Regulars expresion are very powerfull, but the code that
does the matching is a bit more complicated. With like expresions
you may write simple and faster code.


Mirek


Re: [SQL] How to Make Case InSensitive???

От
Bruce Momjian
Дата:
[Charset ISO-8859-2 unsupported, filtering to ASCII...]
>
> > > I working with a table of about 70'000 records and I made 2 tests about
> > > the optimisation of ~* :
> > >
> > > With ~* :
>
> > > real 11.52 *
> > > user 0.02
> > > sys 0.01
> > >
> > > With upper(...) and like upper(%...%)
> > > --------------------------------------
>
> > > real 4.44 *
> > > user 0.03
> > > sys 0.00
> > >
> > > Relsult: it seem to be 2.6 time more optimised to use upper(...) like
> > > upper('%...%') ???
>
> > This is interesting.  Does anyone have an idea why this is happening?
>
> In my opinion the reason why regular expresion matching is sloer is
> obvious. Regulars expresion are very powerfull, but the code that
> does the matching is a bit more complicated. With like expresions
> you may write simple and faster code.

Makes sense.

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