Re: Allow parallel plan for referential integrity checks?

On 3/19/22 01:57, Imseih (AWS), Sami wrote:
> I looked at your patch and it's a good idea to make foreign key validation
> use parallel query on large relations.
>
> It would be valuable to add logging to ensure that the ActiveSnapshot and TransactionSnapshot
> is the same for the leader and the workers. This logging could be tested in the TAP test.
>
> Also, inside RI_Initial_Check you may want to set max_parallel_workers to
> max_parallel_maintenance_workers.
>
> Currently the work_mem is set to maintenance_work_mem. This will also require
> a doc change to call out.
>
> /*
> * Temporarily increase work_mem so that the check query can be executed
> * more efficiently. It seems okay to do this because the query is simple
> * enough to not use a multiple of work_mem, and one typically would not
> * have many large foreign-key validations happening concurrently. So
> * this seems to meet the criteria for being considered a "maintenance"
> * operation, and accordingly we use maintenance_work_mem. However, we
>

Hello Sami,

Thank you for your review!

I will try to do as you say, but it will take time, since my daily job
as database consultant takes most of my time and energy.

Best regards,
Frédéric