Re: Parallel Inserts in CREATE TABLE AS

On Wed, Dec 30, 2020 at 10:32 AM Dilip Kumar <dilipbalaut(at)gmail(dot)com> wrote:
> I have completed reviewing 0001, I don't have more comments, just one
> question. Soon I will review the remaining patches.

Thanks.

> + /* If parallel inserts are to be allowed, set a few extra information. */
> + if (myState->is_parallel)
> + {
> + myState->object_id = intoRelationAddr.objectId;
> +
> + /*
> + * We don't need to skip contacting FSM while inserting tuples for
> + * parallel mode, while extending the relations, workers instead of
> + * blocking on a page while another worker is inserting, can check the
> + * FSM for another page that can accommodate the tuples. This results
> + * in major benefit for parallel inserts.
> + */
> + myState->ti_options = 0;
>
> Is there any performance data for this or just theoretical analysis?

I have seen that we don't get much performance with the skip fsm
option, though I don't have the data to back it up. I'm planning to
run performance tests after the patches 0001, 0002 and 0003 get
reviewed. I will capture the data at that time. Hope that's fine.

With Regards,
Bharath Rupireddy.
EnterpriseDB: http://www.enterprisedb.com