Re: Oracle 12c Inmemory - don't stop thinking
- From: "Kevin Closson" <dmarc-noreply@xxxxxxxxxxxxx> (Redacted sender "ora_kclosson@xxxxxxxxx" for DMARC)
- To: "kevin.jernigan@xxxxxxxxxx" <kevin.jernigan@xxxxxxxxxx>, "usn@xxxxxxxxx" <usn@xxxxxxxxx>, "mark.powell2@xxxxxx" <mark.powell2@xxxxxx>
- Date: Mon, 28 Jul 2014 12:09:59 -0700
If the following parameter was set to DISABLE by default there'd be no
conversation on this matter.
INMEMORY_QUERY This initialization parameter specifies whether in-memory
queries are allowed. Set this parameter toENABLE, the default value, to allow
queries to access database objects populated in the IM column store, or set
this parameter to DISABLE to disable access to the database objects populated
in the IM column store.
________________________________
From: Kevin Jernigan <kevin.jernigan@xxxxxxxxxx>
To: usn@xxxxxxxxx; mark.powell2@xxxxxx
Cc: ORACLE-L <oracle-l@xxxxxxxxxxxxx>
Sent: Monday, July 28, 2014 10:02 AM
Subject: Re: Oracle 12c Inmemory - don't stop thinking
In 12.1.0.2, inmemory_size is set to 0 by default, and unless it has a
non-zero value, usage of the Database In-Memory option will track as
"false". Note that the DBA has to go out of his/her way to set
inmemory_size, as you must restart the db instance for changes to
non-zero values to take effect.
So, it is explicitly NOT TRUE that Database In-Memory is enabled by
default - and it's (IMHO) irresponsible (at best) to suggest otherwise...
-KJ
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Kevin Jernigan
Senior Director Product Management
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Compression (HCC), Database File System
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On 7/28/14, 7:14 AM, Martin Klier wrote:
> Hi,
>
> "enabled by default" - is not exactly true. The INMEMORY pool is zero by
> default, but I must confess I did not check how usage watermarks for the
> option are checked.
>
> Regards
> Martin
>
>
> Am 25.07.2014 18:36, schrieb Powell, Mark:
>> I will add that this feature while enabled by default is extra-cost, very
>> expensive extra-cost at that.
>>
>>
>> -----Original Message-----
>> Oracle tells us that InMemory will care for everything. But as usual, the
>> BUT is well covered. In my recent blog post
>>
>> "Oracle 12c InMemory - don't stop thinking about performance"
>> http://www.usn-it.de/index.php/2014/07/25/oracle-12c-inmemory-dont-stop-thinking-about-performance/--
--
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