Hi Lisa,
You're correct.
I'm sure you know, but I'd like to add that
hash join usually works faster than over
methods
when there are no good selective conditions
in the
clause WHERE.
Regards,
Ed
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
Hi Kevin,
It's quick if you have the temp space
to support it. however with larger tables my experience has been that it
blows temp, isn't that much faster even if you do have the temp space, and in
most cases you are better off with index-driven nested loops join. It
works well with small to medium-sized tables.
Just my .02
List, if I'm wrong, please correct
me.
Lisa Koivu <FONT
face="Book Antiqua" size=2>Oracle Database Administrator <FONT
face=Tahoma size=2>954-935-4117
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-----Original Message----- <FONT
face=Arial size=1>From: Kevin
Kostyszyn [SMTP:kevin_at_dulcian.com] <FONT face=Arial
size=1>Sent: Thursday, May
31, 2001 9:34 AM <FONT face=Arial
size=1>To: <FONT face=Arial
size=1>Multiple recipients of list ORACLE-L <FONT face=Arial
size=1>Subject: <FONT
face=Arial size=1>RE: what's hash-join
What's the performance (gain/loss) on such a
join, when would you want to use
one? Kev
-----Original Message----- <FONT
face=Arial size=2>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 <FONT face=Arial
size=2>connor
- Senthil Ganapathi <FONT face=Arial
size=2><senthil.ganapathi_at_mannai.com.qa> wrote: > <FONT
face=Arial size=2>> Hi Rukmini >
could tell me what's that hash-join <FONT face=Arial
size=2>> > GSK <FONT
face=Arial size=2>> >
> <FONT face=Arial
size=2>> <FONT face=Arial
size=2>>
"Rukmini > <FONT face=Arial
size=2>>
Devi"
To: > Multiple recipients of list
ORACLE-L <FONT face=Arial
size=2>>
<rukmini_at_indb >
<ORACLE-L_at_fatcity.com> <FONT face=Arial
size=2>>
rain.com>
cc: > <FONT face=Arial
size=2>>
Sent
by:
Subject: > Re: 4 join
methods? <FONT face=Arial
size=2>>
root_at_fatcity. > <FONT
face=Arial
size=2>>
com > <FONT face=Arial
size=2>> > <FONT
face=Arial size=2>> >
<FONT face=Arial
size=2>>
31-05-01 > <FONT face=Arial
size=2>>
09:55 AM > <FONT face=Arial
size=2>>
Please > <FONT face=Arial
size=2>>
respond to > <FONT
face=Arial
size=2>>
ORACLE-L > <FONT face=Arial
size=2>> > <FONT
face=Arial size=2>> >
> <FONT face=Arial
size=2>> > <FONT
face=Arial size=2>> > 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 <FONT face=Arial
size=2>> > <FONT
face=Arial size=2>> > i feel the fourth one is self join.
> > <FONT face=Arial
size=2>> > ----- Original Message ----- <FONT face=Arial
size=2>> > To: Multiple recipients of list ORACLE-L <FONT
face=Arial size=2>> <ORACLE-L_at_fatcity.com> <FONT
face=Arial size=2>> > Sent: Thursday, May 31, 2001 8:10 AM
> > <FONT face=Arial
size=2>> > > > >
Hi, > > > <FONT
face=Arial size=2>> > > I just read there are four join
methods. I know > three:
> > > <FONT face=Arial
size=2>> > > Nested loops >
> > Sort merge > > > Hash
join > > > <FONT
face=Arial size=2>> > > What's the fourth? <FONT
face=Arial size=2>> > > >
> > - Greg > > >
> > > -- <FONT face=Arial
size=2>> > > Please see the official ORACLE-L FAQ: <FONT
face=Arial size=2>> <A target=_blank
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face=Arial size=2>> > > -- >
> > Author: Greg Moore > >
> INET: sqlgreg_at_pacbell.net <FONT face=Arial
size=2>> > > > > > Fat
City Network Services -- (858) 538-5051 <FONT
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> Fat City Network Services
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Received on Thu May 31 2001 - 14:37:45 CDT
