Delete query on materialized view

Hi all

I am trying to delete/insert a row on materialized view which has join from a UDF by using SPI_execute.

Materialized views are not allowed to do any DML changes once created,so by bypassed that check by enabling MatViewIncrementalMaintenanceIsEnabled. so DML queries can be executed in MV. But i dont want to bypass that check i tried to change the relkind for the materialized view to 'r' (normal table relation) in pg_class table and tried the same query but its throwing an error.

## ERROR: could not find attribute -1 in subquery targetlist ##

Is there a way to enable DML queries on materialized views which has join without overwriting matview_maintenance_depth to 1 as the method was local in matview.c?

cheers

- Harry