Re: Parallel Inserts in CREATE TABLE AS

On Wed, Dec 30, 2020 at 7:47 PM Bharath Rupireddy
<bharath(dot)rupireddyforpostgres(at)gmail(dot)com> wrote:
>
> Thanks for the comments.
>
> How about naming like below more generically and placing them in
> parallel.h so that it will also be used for refresh materialized view?
>
> +typedef enum ParallelInsertTupleCostOpt
> +{
> + PINS_SELECT_QUERY = 1 << 0, /* turn on this before planning */
> + /*
> + * Turn on this while planning for upper Gather path to ignore parallel
> + * tuple cost in cost_gather.
> + */
> + PINS_CAN_IGN_TUP_COST = 1 << 1,
> + /* Turn on this after the cost is ignored. */
> + PINS_TUP_COST_IGNORED = 1 << 2
>
> My plan was to get the main design idea of pushing the dest receiver
> to gather reviewed and once agreed, then I thought of making few
> functions common and place them in parallel.h and parallel.c so that
> they can be used for Parallel Inserts in REFRESH MATERIALIZED VIEW
> because the same design idea can be applied there as well.

I think instead of PINS_* we can name PARALLEL_INSERT_* other than
that I am fine with the name.

> For instance my thoughts are: add the below structures, functions and
> other macros to parallel.h and parallel.c:
> typedef enum ParallelInsertKind
> {
> PINS_UNDEF = 0,
> PINS_CREATE_TABLE_AS,
> PINS_REFRESH_MAT_VIEW
> } ParallelInsertKind;
>
> typedef struct ParallelInsertCTASInfo
> {
> IntoClause *intoclause;
> Oid objectid;
> } ParallelInsertCTASInfo;
>
> typedef struct ParallelInsertRMVInfo
> {
> Oid objectid;
> } ParallelInsertRMVInfo;
>
> ExecInitParallelPlan(PlanState *planstate, EState *estate,
> Bitmapset *sendParams, int nworkers,
> - int64 tuples_needed)
> + int64 tuples_needed, ParallelInsertKind pinskind,
> + void *pinsinfo)
>
> Change ExecParallelInsertInCTAS to
>
> +static void
> +ExecParallelInsert(GatherState *node)
> +{
>
> Change SetCTASParallelInsertState to
> +void
> +SetParallelInsertState(QueryDesc *queryDesc)
>
> Change IsParallelInsertionAllowedInCTAS to
>
> +bool
> +IsParallelInsertionAllowed(ParallelInsertKind pinskind, IntoClause *into)
> +{
>
> Thoughts?
>

I haven’t thought about these structures yet but yeah making them
generic will be good.

--
Regards,
Dilip Kumar
EnterpriseDB: http://www.enterprisedb.com