It will perform better than sort and merge and nested loops in most cases.
They tend to be fast. But will not out perform index nested loops in most
cases.
Although in some cases a sort and merge can out perform a hash join.
"Walking on water and developing software from a specification are easy if
both are frozen."
Christopher R. Spence
Oracle DBA
Fuelspot
-----Original Message-----
Sent: Thursday, May 31, 2001 9:34 AM
To: Multiple recipients of list ORACLE-L
What's the performance (gain/loss) on such a join, when would you want to
use one?
Kev
-----Original Message-----
McDonald
Sent: Thursday, May 31, 2001 6:00 AM
To: Multiple recipients of list ORACLE-L
A method of joining two tables. You scan each and use
a hashing algorithm to isolate/match keys.
hth
connor
- Senthil Ganapathi
<senthil.ganapathi_at_mannai.com.qa> wrote: >
> Hi Rukmini
> could tell me what's that hash-join
>
> GSK
>
>
>
>
> "Rukmini
>
> Devi" To:
> Multiple recipients of list ORACLE-L
> <rukmini_at_indb
> <ORACLE-L_at_fatcity.com>
> rain.com> cc:
>
> Sent by: Subject:
> Re: 4 join methods?
> root_at_fatcity.
>
> com
>
>
>
>
>
> 31-05-01
>
> 09:55 AM
>
> Please
>
> respond to
>
> ORACLE-L
>
>
>
>
>
>
>
>
>
> 1. Equi-join 2. Self-join 3. Outer-join 4.
> Hash-join
>
> rukmini
> ----- Original Message -----
> To: "Multiple recipients of list ORACLE-L"
> <ORACLE-L_at_fatcity.com>
> Sent: Thursday, May 31, 2001 11:20 AM
>
>
> > i feel the fourth one is self join.
> >
> > ----- Original Message -----
> > To: Multiple recipients of list ORACLE-L
> <ORACLE-L_at_fatcity.com>
> > Sent: Thursday, May 31, 2001 8:10 AM
> >
> >
> > > Hi,
> > >
> > > I just read there are four join methods. I know
> three:
> > >
> > > Nested loops
> > > Sort merge
> > > Hash join
> > >
> > > What's the fourth?
> > >
> > > - Greg
> > >
> > > --
> > > Please see the official ORACLE-L FAQ:
> http://www.orafaq.com
> > > --
> > > Author: Greg Moore
> > > INET: sqlgreg_at_pacbell.net
> > >
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> --
> Please see the official ORACLE-L FAQ:
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> --
> Author: Rukmini Devi
> INET: rukmini_at_indbrain.com
>
> Fat City Network Services -- (858) 538-5051 FAX:
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> To REMOVE yourself from this mailing list, send an
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> --
> Please see the official ORACLE-L FAQ:
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> --
> Author: Senthil Ganapathi
> INET: senthil.ganapathi_at_mannai.com.qa
>
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Received on Thu May 31 2001 - 09:47:14 CDT
