create table Resource (
    resource_id       serial    primary key,
    parent_id         int       references Resource(resource_id),
    nodename          text      not null,
    iscollection      boolean   not null default false,
	
    lastmodified      timestamp not null default current_date,
    creationdate      timestamp not null default current_date,
    contentlength     bigint    not null default 0,

    resoid            oid,
    
    unique(parent_id, nodename)
);