Postgres can operate over transaction DDL but in most cases I think this would be a fine thing to isolate over - the more worrying case is when different transa

Postgres can operate over transaction DDL but in most cases I think this would be a fine thing to isolate over - the more worrying case is when different transaction spaces have different understandings of row statistics - PG does use row statistics to inform planning so it's not inconceivable that sharing a plan between two queries running in vastly different data states would result in a highly inefficient query.