Return-Path: Received: from newsfeed.cts.com (newsfeed.cts.com [209.68.248.164]) by naude.co.za (8.11.2/8.11.2) with SMTP id g7SDMDO26863 for ; Wed, 28 Aug 2002 09:22:13 -0400 Received: from fatcity.UUCP (uucp@localhost) by newsfeed.cts.com (8.9.3/8.9.3) with UUCP id GAA09614; Wed, 28 Aug 2002 06:20:54 -0700 (PDT) Received: by fatcity.com (26-Feb-2001/v1.0g-b72/bab) via UUCP id 004C14ED; Wed, 28 Aug 2002 05:53:29 -0800 Message-ID: Date: Wed, 28 Aug 2002 05:53:29 -0800 To: Multiple recipients of list ORACLE-L X-Comment: Oracle RDBMS Community Forum X-Sender: "Altizer, Bronwyn K." Sender: root@fatcity.com Reply-To: ORACLE-L@fatcity.com Errors-To: ML-ERRORS@fatcity.com From: "Altizer, Bronwyn K." Subject: RE: rman question(allocating channels) Organization: Fat City Network Services, San Diego, California X-ListServer: v1.0g, build 72; ListGuru (c) 1996-2001 Bruce A. Bergman Precedence: bulk Mime-Version: 1.0 Content-Type: multipart/alternative; boundary="----_=_NextPart_001_01C24E90.FEEC2060" ------_=_NextPart_001_01C24E90.FEEC2060 Content-Type: text/plain; charset="iso-8859-1" Yep its me answering a question for you for a change - I was able to bounce your question off of Dinis (our RMAN guru) and he said: ( Yeah I could have pretended that I knew the answer but I don't think you would have fallen for that!) Channels are streams. Basically when you have multiple channels (lets say 4 channel) you can write to take or disk with 4 streams at the same time, which means that you will be able to backup more datafiles concurrently. No channels are not related to CPU or destinations. Yes it makes sense that you allocate more channels because it will shorten you backup time but then again the more channels you use the more resources you will be using on the server that you are backing up the database. I hope this answers your question but if not please let me know. P.S. Each channel will correspond to a session in the database that is being backed up. -----Origin al Message----- Sent: Wednesday, August 28, 2002 8:38 AM To: Multiple recipients of list ORACLE-L I've tried to find this in the docs to no avail. If I'm writing out an RMAN backup to one disk(yes this is not ideal), then does it make sense to allocate multiple channels? Are multiple channels related to CPUs or to destinations? thanks, joe ------_=_NextPart_001_01C24E90.FEEC2060 Content-Type: text/html; charset="iso-8859-1"
Yep its me answering a question for you for a change - I was able to bounce your question off of Dinis (our RMAN guru) and he said:   ( Yeah I could have pretended that I knew the answer but I don't think you would have fallen for that!)
 
Channels are streams. Basically when you have multiple channels (lets say 4 channel) you can write to take or disk with 4 streams at the same time, which means that you will be able to  backup more datafiles concurrently. No channels are not related to CPU or destinations. Yes it makes sense that you allocate more channels because it will shorten you backup time but then again the more channels you use the more resources you will be using on the server that you are backing up the database. I hope this answers your question but if not please let me know.
 
 
P.S. Each channel will correspond to a session in the database that is being backed up.
-----Origin al Message-----
From: JOE TESTA [mailto:JTESTA@longaberger.com]
Sent: Wednesday, August 28, 2002 8:38 AM
To: Multiple recipients of list ORACLE-L
Subject: rman question(allocating channels)

I've tried to find this in the docs to no avail.
 
If I'm writing out an RMAN backup to one disk(yes this is not ideal), then does it make sense to allocate multiple channels?
 
Are multiple channels related to CPUs or to destinations?
 
thanks, joe
 
 
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