Re: Oracle 12c Inmemory - don't stop thinking
From: Kevin Closson <ora_kclosson_at_yahoo.com>
Date: Mon, 28 Jul 2014 12:09:59 -0700
Message-ID: <1406574599.62279.YahooMailNeo_at_web121203.mail.ne1.yahoo.com>
Date: Mon, 28 Jul 2014 12:09:59 -0700
Message-ID: <1406574599.62279.YahooMailNeo_at_web121203.mail.ne1.yahoo.com>
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_at_oracle.com> To: usn_at_usn-it.de; mark.powell2_at_hp.com Cc: ORACLE-L <oracle-l_at_freelists.org> 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/-- -- http://www.freelists.org/webpage/oracle-l
-- http://www.freelists.org/webpage/oracle-lReceived on Mon Jul 28 2014 - 21:09:59 CEST