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.fall...@gmail.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! >
