To simplify: Can CustomScan scan multiple relations in the same query or it
will always be assigned to one or zero relations?
On Fri, Apr 14, 2023 at 4:33 PM Amin <amin(dot)fallahi(at)gmail(dot)com> wrote:
> Hi there,
>
> In my implementation of CustomScan, when I have a query that scans
> multiple tables (select c from t1,t2,t3), the planner always picks one
> table to be scanned by CustomScan and offloads the rest to SeqScan. I tried
> assigning a cost of 0 to the CustomScan path, but still not working.
> BeginCustomScan gets executed, ExecCustomScan is skipped, and then
> EndCustomScan is executed for all the tables that are offloaded to Seq
> Scan. EXPLAIN shows that always only one table is picked to be executed by
> CustomScan. Any idea what I might be doing wrong? Like a value in a struct
> I might be setting incorrectly?
>
> Thanks!
>