-- with schema1
create or replace procedure schema1.EXECUTE_RAW_SQL ( statement in varchar2 )
is begin
    execute immediate statement;
exception when others then
   raise_application_error(-20001,'An error was encountered - '||SQLCODE||' -ERROR- '||SQLERRM);
end;

-- with dba
create user schema2 identified by schema2;
grant connect to schema2;
grant create session to schema2;
grant execute on schema1.EXECUTE_RAW_SQL to schema2;

-- with schema2
execute schema1.EXECUTE_RAW_SQL('create table blah ( id number(10), name varchar2(255) )');
-- Error starting at line : 1 in command -
-- BEGIN schema1.EXECUTE_RAW_SQL('create table blah ( id number(10), name varchar2(255) )'); END;
-- Error report -
-- ORA-20001: An error was encountered - -1031 -ERROR- ORA-01031: insufficient privileges
-- ORA-06512: at "schema1.EXECUTE_RAW_SQL", line 5
-- ORA-06512: at line 1

-- with dba
grant create table to schema1;

-- with schema2
execute schema1.EXECUTE_RAW_SQL('create table blah ( id number(10), name varchar2(255) )');

-- with schema1
describe blah;
-- Name Null? Type
-- ---- ----- -------------
-- ID         NUMBER(10)
-- NAME       VARCHAR2(255)