Re: Doubt in mvcc

On 7/13/20 12:31 AM, Rama Krishnan wrote:
>
>
> Hi sir,
>
> I m preparing for interview one of the recruiter asked me mvcc drawbacks
> as i told due to mvcc it use more space and need to perform maintenance
> activity.
>
> Another one is the same data causes an update conflict because two
> different transactions can update the same version of the row.
>  he told its wrong, kindly tell me will you please tell me its correct
> or wrong?

It depends on what you are calling a conflict and what isolation level
you are in. Take a look at this section of the docs:

https://www.postgresql.org/docs/12/transaction-iso.html
>
>
> Thanks
> RK

--
Adrian Klaver
adrian(dot)klaver(at)aklaver(dot)com