Re: Oracle 12c Inmemory - don't stop thinking

  • From: "Kevin Closson" <dmarc-noreply@xxxxxxxxxxxxx> (Redacted sender "ora_kclosson@xxxxxxxxx" for DMARC)
  • To: "kerry.osborne@xxxxxxxxxxx" <kerry.osborne@xxxxxxxxxxx>
  • Date: Mon, 28 Jul 2014 14:30:59 -0700

I see your point Kerry.  Would you concede that, perhaps, just perhaps, 
shipping with the top-level parameter INMEMORY_QUERY set to DISABLE would be a 
little more sensible? That's how RAC is..top-level disabled.

> Then you have to tell Oracle which objects you want to populate the column 
>store with, generally with an alter table or alter partition statement per 
>object.

This is not correct. I proved otherwise in Part II. You may argue the proof was 
too far fetched as you wish and I won't argue that. 



________________________________
 From: Kerry Osborne <kerry.osborne@xxxxxxxxxxx>
To: Kevin Closson <ora_kclosson@xxxxxxxxx> 
Cc: "kevin.jernigan@xxxxxxxxxx" <kevin.jernigan@xxxxxxxxxx>; "usn@xxxxxxxxx" 
<usn@xxxxxxxxx>; "mark.powell2@xxxxxx" <mark.powell2@xxxxxx>; ORACLE-L 
<oracle-l@xxxxxxxxxxxxx> 
Sent: Monday, July 28, 2014 12:45 PM
Subject: Re: Oracle 12c Inmemory - don't stop thinking
 


Come on dude - you aren't making any sense. In order to enable this feature you 
have to set an init parameter (inmemory_size) to a value > 0 (which is the 
default) and then bounce the database (bounce the database dude!). Then you 
have to tell Oracle which objects you want to populate the column store with, 
generally with an alter table or alter partition statement per object. On what 
planet is that equivalent to "enabled by default"? Any DBA that takes all those 
steps and then claims they have been tricked into using the feature should have 
their head examined. Sorry but your claim that the inmemory_query parameter 
being set to ENABLED is a problem just doesn't hold water. 


Kerry Osborne
Enkitec
blog: kerryosborne.oracle-guy.com
twitter: https://twitter.com/KerryOracleGuy










On Jul 28, 2014, at 2:09 PM, Kevin Closson (Redacted sender 
"ora_kclosson@xxxxxxxxx" for DMARC) wrote:

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
>
>-- 
>Kevin Jernigan
>Senior Director Product Management
>Advanced Compression, Hybrid Columnar
>Compression (HCC), Database File System
>(DBFS), SecureFiles, Database Smart Flash
>Cache, Total Recall, Database Resource
>Manager (DBRM), Direct NFS Client (dNFS),
>Continuous Query Notification (CQN),
>Index Organized Tables (IOT), Information
>Lifecycle Management (ILM)
>+1-650-607-0392 (o)
>+1-415-710-8828 (m)
>
>
>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/--
>
>--
>//www.freelists.org/webpage/oracle-l
>
>
>
>
>

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