create table ns (
prefix char(16),
uri char(255)
);
create table node (
id serial primary key,
created timestamp,
value text,
is_resource integer
);
create table statement (
id serial primary key,
created timestamp,
subject integer,
predicate integer,
object integer,
context integer
);
create index subject on statement (subject);
create index predicate on statement (predicate);
create index object on statement (object);
create index context on statement (context);