Re: Streams advice

From: DA Morgan <>
Date: Fri, 23 May 2008 10:41:48 -0700
Message-ID: <>

Geoff Muldoon wrote:
> DA Morgan says...

>> Geoff Muldoon wrote:
>>> Frank van Bortel says...
>>>> Geoff Muldoon wrote:
>>>>> We are particularly looking at Asynchronous Change Data Capture because it 
>>>>> "can be configured to have minimal performance impact on the source 
>>>>> database", so I presume you refer to overheads at the staging database and 
>>>>> overall server resource levels, rather than within the source databases.  
>>>>> Maybe overheads of the subscriber databases too?
>>>> No - source. Hopefully, things have improved with 10G; was
>>>> simply a disaster.
>>> Performance within the source?  Thought that the only real additional 
>>> overhead there would be the requirement to bump to supplemental rather 
>>> than standard logging. Does the log mining process affect performance 
>>> within the source database process?

>> Log Miner is very resource intensive. Don't be surprised if it eats a
>> substantial percentage of your server's capabilities.

> Thanks for the heads up on that. Might look for our prototype at running
> the Streams staging instance on separate hardware to isolate resource
> contention from the OLTP source systems.
> Do Redo Transport Services chew much resources on the source systems or,
> if significant, is that mainly in the staging area as well? I'm assuming
> that Log Miner runs in the model we're considering (Asynchronous Autolog
> Mode) on the staging server post log transportation, rather than on the
> source servers.
> Geoff M

Redo transport is not that resource intensive, neither is streams. Log Miner is doing a large amount of work reading log files, analyzing their content, and reconstructing the transactions.

Daniel A. Morgan
Oracle Ace Director & Instructor
University of Washington (replace x with u to respond)
Puget Sound Oracle Users Group
Received on Fri May 23 2008 - 12:41:48 CDT

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