See which tables are called in a view

viewtables.sql

CREATE OR REPLACE FUNCTION public.viewtables(viewname text)
 RETURNS SETOF text
 LANGUAGE plperl
AS $function$
my $viewname = shift;
my $rv = spi_exec_query("explain (format yaml, verbose) SELECT * FROM $viewname");
my $resp = $rv->{rows}[0]->{'QUERY PLAN'};
my %tbls;
while ($resp =~ /Relation Name: (".*")\n\s+Schema: (".*")\n/g) 
{
   $tbls{"$2.$1"} = 1;
}
return [sort keys %tbls];
$function$
;