Re: Hugepages usage

Well, by that comment I was referring to the pre-page sga setting only. With regard to the hugepage settings, typically you notice substantially less CPU usage, especially on VMs. in my experience, it was about a 5% reduction of CPU usage on physical servers, and somewhere between 10-20% reduction on virtual servers.

On Tue, Feb 11, 2020 at 10:20 AM Ram K <lambu999_at_gmail.com> wrote:

> This was going to be my next question: " I haven’t noticed any performance
> gain from setting it true" .
>
> How do I measure the performance gain? WIth 32Gb and 4K page size we are
> looking at 8.3M memory pages; with 32G and 2M page size, we have 16K pages.
> Will the responses be faster esp, with cases where several pages need to be
> scanned? The DB equivalent I can think of is full table or index scans.
>
> I was also also looking up the lock_sga setting. I am left wondering why
> we even have the choice to set LOCK_SGA to FALSE. Should it not be true all
> the time? The manual
> <https://docs.oracle.com/en/database/oracle/oracle-database/12.2/refrn/LOCK_SGA.html#GUID-83BBA5B8-0E01-4B10-8278-AE4EEE39328B>
> says that "This parameter is ignored on platforms that do not support it"
>
>
>
> On Mon, Feb 10, 2020 at 7:39 PM Andrew Kerber <andrew.kerber_at_gmail.com>
> wrote:
>
>> It can slow down the startup, but usually not a lot. However, I haven’t
>> noticed any performance gain from setting it true since 10.2.
>>
>> Sent from my iPad
>>
>> > On Feb 10, 2020, at 19:35, Mladen Gogala <gogala.mladen_at_gmail.com>
>> wrote:
>> >
>> > Pre-paging SGA will slow down your DB considerably. 32 GB is a small
>> SGA,but it will still slow down the startup of your database.
>> >
>> >> On 2/10/20 6:43 PM, Ram K wrote:
>> >>
>> >> pre_page_sga boolean
>> TRUE
>> >
>> > --
>> > Mladen Gogala
>> > Database Consultant
>> > Tel: (347) 321-1217
>> >
>> > --
>> > http://www.freelists.org/webpage/oracle-l
>> >
>> >
>> --
>> http://www.freelists.org/webpage/oracle-l
>>
>>
>>
>
> --
> Thanks,
> Ram.
>

-- 
Andrew W. Kerber

'If at first you dont succeed, dont take up skydiving.'

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