Re: Parallel Inserts in CREATE TABLE AS

On Wed, Dec 30, 2020 at 10:32 AM Dilip Kumar <dilipbalaut@gmail.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