Re: Question on IO consideration

Agreed. Many times things may not be much helpful in real life scenario unless used in correct usecase and can introduce other issues. So better to start safe and hear from someone who already used these options to cater IO issues in similar scale db etc.

On Wed, 22 Sep 2021, 1:26 am Lok P, <loknath.73_at_gmail.com> wrote:

> Thank You Mark.
>
> I see it's available starting with version 12C. In one of our 19C
> databases I see in gv$parameter , we have inmemeory_force 'default'
> inmemory_query 'enable'. So we can try experimenting with it on a test
> database by tweaking a few table designs and running a workload to see the
> difference in reduction in IO. And as it seems this in memory column store
> is actually a hybrid architecture of row+column store and the column store
> is going to be stored in buffer cache only which is not a persistent
> storage area, so is it really recommended and going to make a difference in
> IO/Performance for big databases , say 100TB-200TB in size in a real life
> scenario? I may be thinking it in dumb way of requirement of buffer cache
> in TB's.
>
> And just curious to know, Is this additional licensing because of which
> people are not using it or it's not much in use or popular? because even in
> this forum i never saw questions/discussions on any database with in
> memory columnar feature used. Or are there some drawbacks that come with it
> in real life scenarios, if we use that option?
>
> On Wed, Sep 22, 2021 at 12:34 AM Powell, Mark <mark.powell2_at_dxc.com>
> wrote:
>
>> Lok, the extra-cost Oracle In-memory feature supports column store
>> tables/indexes
>>
>> In-Memory Column Store Architecture (oracle.com)
>> <https://docs.oracle.com/en/database/oracle/oracle-database/19/inmem/in-memory-column-store-architecture.html#GUID-EEA265EE-8FBA-4457-8C3F-315B9EEA2224>
>>
>> Mark Powell
>> Database Administration
>> (313) 592-5148
>>
>>
>> ------------------------------
>> *From:* oracle-l-bounce_at_freelists.org <oracle-l-bounce_at_freelists.org> on
>> behalf of Lok P <loknath.73_at_gmail.com>
>> *Sent:* Tuesday, September 21, 2021 2:48 PM
>> *To:* Oracle L <oracle-l_at_freelists.org>
>> *Subject:* Question on IO consideration
>>
>> Hello Listers, We have oracle exadata databases which are performing
>> mostly warehousing or batch type data processing. And few are hybrid i.e
>> combination of both oltp+warehousing/analytics types processing. ETL jobs
>> run on a few of these which move/read/write billions rows daily.
>> The databases are 50TB to ~150TB in size currently. Few architecture
>> team members suggested evaluating if we can use columnar database type of
>> offering for IO reduction and thus better performance considering the
>> future growth. As per my understanding , Oracle stores data in row format
>> only, so is there any other offering from Oracle for columnar datastore
>> format or columnar databases and we should evaluate that? Or is there any
>> clustering kind of technique which can be evaluated which will help reduce
>> IO? Want to understand experts' views here on this.
>>
>> Regards
>> Lok
>>
>>
>>

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