Re: Sequnce Cache Size in RAC

This is how a (default) no order sequence behaves. Eg if you set cache size 5 and had two nodes the following sequence values could be chosen in chronological order with uneven distribution of requests:

Node 1: 1 (gets 1-5)
Node 2: 6 (gets 6–10)
Node 1: 2
Node 1: 3
Node 1: 4
Node 1: 5
Node 1: 11 (gets 11-15)
Node 2: 7

> Hi Experts,
> Intention to raise this question was , some of my
> colleagues suggested that increase in cache size from 0 to bigger number
> can cause difference in cache value from both node .
>
> like in my case , cache size is 0 , and this is RAC environment , so in
> this case , certain numbers are cached in node 1 and a separate set will be
> cached for node 2 .
>
> so any maily insert using this sequence can cause issue of difference in
> number
>
> Please share some light on this .
>
> Regards,
> Krishna
>
>
> On Tue, 15 Feb 2022 at 16:45, Laurentiu Oprea <laurentiu.oprea06_at_gmail.com>
> wrote:
>
>> Hello Krishna,
>>
>> Your question is really incomplete, thus the answers you are getting are
>> in consequence.
>>
>> You might need to provide details on:
>> -> why the cache was initially set to 0
>> -> what drives the motivation to increase the cache and what kind of
>> investigations was undertaken to conclude that the issues will be solved by
>> this
>> -> what version your database is running
>>
>> You might want to read these articles by Jonathan Lewis:
>> https://jonathanlewis.wordpress.com/2022/02/07/sequence-catalogue/
>> and also this article maybe:
>> https://oracle-base.com/articles/18c/scalable-sequences-18c
>>
>> Thanks.
>>
>> PS: to answer your specific question: increasing cache size for sequences
>> in your environment may or may not create issues.
>>
>> În mar., 15 feb. 2022 la 12:31, Krishnaprasad Yadav <
>> chrishna0007_at_gmail.com> a scris:
>>
>>> Hi Experts ,
>>>
>>> We are proactively trying to increase sequence cache size , currently
>>> the database is in RAC .
>>> I need to know if there is a RAC environment , increase in CACHE size
>>> of sequence makes any difference . Currently the value is cache_size is 0
>>> Does changing value from 0 to 50 of cache_size can cause any issue
>>> w.r.t to application .
>>>
>>>
>>> Regards,
>>> Krishna
>>>
>>>
>>>
>>>
>>>

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