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Home -> Community -> Mailing Lists -> Oracle-L -> RE: HIGH WATER MARK
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The high water mark is the same concept than the water of the dock or =
the
sea-ports...
when water raises up, then you can see in the dock where the top was =
the
wather...
... that's the same with Oracle Blocks...
so, if you use "direct inserts", Oracle needs to manage COMPLETE empty blocks... and that's using the HWM as a reference...
let's take a look at my nice ascii art !! ;-P
|----| |----| |----| |----| |----| |----|
|40% | |0% | |60% | |0% | |0% | |0% |
|used| |Used| |Used| | | | | | |
| | | | | | | | | | | |
|----| |----| |----| |----| |----| |----|
^ =20
| =20
HWM
=20
So, imagine that you delete a table with DELETE FROM... It doesn't =
move
the HWM, so if you delete this way and insert direct, you will find =
that the
table increases size :( ... that's why the best is making full deletes =
with
TRUNCATE TABLE if possible.
Hope this would help! ;-)
---------------------------------------=20Javier Morales - javier_at_infojobs.net=20 Administraci=F3n Bases de Datos Oracle - InfoJobs.net=20 Tel. +34 902 10 60 90 Ext. 2067=20
=20
=20
=20
=20
=20
-----Mensaje original-----
De: Dash, Saroj (CAP,CEF) [ mailto:Saroj.Dash_at_gecapital.com
<mailto:Saroj.Dash_at_gecapital.com> ]
Enviado el: jueves 2 de noviembre de 2000 3:01
Para: Multiple recipients of list ORACLE-L
Asunto: ?: HIGH WATER MARK
Hello Dbas,
What do you mean By High water mark ?? In OEM the rollback segment =
shows the
High water mark.
Please tell me the concept l about that.
Saroj.
-- Please see the official ORACLE-L FAQ: http://www.orafaq.com <http://www.orafaq.com>=20 -- Author: Dash, Saroj (CAP,CEF) INET: Saroj.Dash_at_gecapital.com Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). ------_=_NextPart_001_01C044B5.CDEABD30 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META HTTP-EQUIV=3D"Content-Type" CONTENT=3D"text/html; = charset=3Diso-8859-1"> <TITLE></TITLE> <META content=3D"MSHTML 5.00.2314.1000" name=3DGENERATOR></HEAD> <BODY> <P><FONT size=3D2><FONT face=3DVerdana>The high water mark is the same = concept than=20 the water of the dock or the sea-ports...<BR><BR>when water raises up, = then you=20 can see in the dock where the top was the wather...<BR>... that's the = same with=20 Oracle Blocks...<BR><BR><BR>so, if you use "direct inserts", Oracle = needs to=20 manage COMPLETE empty blocks... and that's using the HWM as a=20 reference...<BR><BR>let's take a look at my nice ascii art !! =20 ;-P<BR><BR></FONT><FONT face=3DCourier><FONT = face=3DCourier>|----| =20Received on Thu Nov 02 2000 - 04:08:55 CST
|----| |----| |----| |----| |----|<BR>|40% | =
|0% =20
| |60% | |0% | |0% | |0% |<FONT=20
face=3DCourier><BR>|used| |Used| |Used| | = |=20
| | | |<FONT=20
face=3DCourier><BR>| | | =
| | =20
| | | | | | =
|<FONT=20
face=3DCourier><BR><FONT face=3DCourier>|----| |----| =
|----| =20
|----| |----| |----|<FONT face=3DCourier><BR><FONT=20
face=3DCourier> &nb= sp; &nb= sp;=20 ^  = ; =20 <FONT face=3DCourier><BR><FONT=20 face=3DCourier> &nb= sp; =20 |  = ;  = ; =20 <FONT face=3DCourier><BR><FONT=20 face=3DCourier> &nb= sp; =20 =20 HWM</FONT></FONT></FONT></FONT></FONT></FONT></FONT></FONT></FONT></FONT= ></FONT></FONT></FONT></P> <P><FONT size=3D2><FONT face=3DCourier><FONT face=3DCourier><FONT = face=3DCourier><FONT=20 face=3DCourier><FONT face=3DCourier><FONT face=3DCourier><FONT = face=3DCourier><FONT=20 face=3DCourier><FONT face=3DCourier><FONT face=3DCourier><FONT = face=3DCourier><FONT=20 face=3DCourier> &nb= sp; <FONT=20 face=3DCourier><BR><FONT face=3DCourier>Oracle wouldn't write in the = 2ond block for=20 a direct insert or a data loading with SQL*Loader, that's because = Oracle needs=20 to know exactly that the blocks are complete=20 free.</FONT></FONT></FONT></FONT></FONT></FONT></FONT></FONT></FONT></FO= NT></FONT></FONT></FONT></FONT></FONT></P> <P><FONT face=3DVerdana size=3D2>So, imagine that you delete a table=20 with DELETE FROM... It doesn't move the HWM, so = if you=20 delete this way and insert direct, you will find that the table = increases size=20 :( ... that's why the best is making full deletes with TRUNCATE = TABLE if=20 possible.</FONT></P> <P><FONT face=3DVerdana size=3D2>Hope this would help! = ;-)</FONT></P> <P><FONT face=3DVerdana=20 size=3D2> ---------------------------------------</FONT> <BR><FONT = face=3DVerdana size=3D2> Javier Morales - = javier_at_infojobs.net</FONT>=20 <BR><FONT face=3DVerdana size=3D2> Administraci=F3n Bases de Datos = Oracle -=20 InfoJobs.net</FONT> <BR><FONT face=3DVerdana size=3D2> Tel. = +34 </FONT>=20 <FONT face=3DVerdana size=3D2>902 10 60 90</FONT><FONT face=3DVerdana = size=3D2> =20 Ext. 2067</FONT> <BR><FONT face=3DVerdana size=3D2> Fax. +34 (93) = 580 56=20 60</FONT> <BR><FONT face=3DVerdana size=3D2> </FONT> </P> <P><BR> </P> <P> </P> <P> </P> <P> </P> <P> </P> <P><FONT size=3D2>-----Mensaje original-----<BR>De: Dash, Saroj = (CAP,CEF) [<A=20 href=3D"mailto:Saroj.Dash_at_gecapital.com">mailto:Saroj.Dash_at_gecapital.com= </A>]<BR>Enviado=20 el: jueves 2 de noviembre de 2000 3:01<BR>Para: Multiple recipients of = list=20 ORACLE-L<BR>Asunto: ?: HIGH WATER MARK<BR><BR><BR>Hello = Dbas,<BR><BR>What do you=20 mean By High water mark ?? In OEM the rollback segment shows = the<BR>High water=20 mark.<BR><BR>Please tell me the concept l about=20 that.<BR><BR>Saroj.<BR><BR>--<BR>Please see the official ORACLE-L FAQ: = <A=20 href=3D"http://www.orafaq.com"=20 target=3D_blank>http://www.orafaq.com</A><BR>--<BR>Author: Dash, = Saroj =20 (CAP,CEF)<BR> INET: Saroj.Dash_at_gecapital.com<BR><BR>Fat City = Network=20 Services -- (858) 538-5051 FAX: (858) = 538-5051<BR>San=20 Diego, California -- Public = Internet=20 access / Mailing=20 Lists<BR>---------------------------------------------------------------= -----<BR>To=20 REMOVE yourself from this mailing list, send an E-Mail message<BR>to:=20 ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in<BR>the = message=20 BODY, include a line containing: UNSUB ORACLE-L<BR>(or the name of =
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