Reference no: EM132015

1) Prepare directories on your hard drive. Place a small text file in one directory. Use Oracle package UTL_FILE to read that file, line by line, from one directory and write a similarly named file into the second directory. Before writing the file to the second directory check whether a file with the intended file already exists in that directory. If it does, do not overwrite it but rather rename that existing file (create a backup copy).

2) Prepare an indefinitely running process that would insert a single row with a numeric primary key in one column and some kind of time stamp in the other column. Between two insertions, what 10 seconds. Control the wait between two insertions using Oracle packaged procedure:

dbms_lock.sleep(Number_of_seconds );

You do want to have a way of telling that process to stop. Use tools given by Oracle's dbms_pipe package. Let that process periodically read a named pipe. If there appears a message "STOP" in that pipe, the process should stop.

3) Prepare a object types emp_t, dept_t, andoffice_t where type emp_t will have information on employees empno, ename, managerrefanddeptref. Field managerref is the reference (pointer) to an emp_t object containing description of an employee's manager. Similarly, deptref is the reference to an object of type dept_t. Type dept_t contains information about a department, i.e. deptno, dname, location (city) and officeref. Field officeref is a reference pointing to an object of type office_t which describes an office building. Type office_t contains attributes specifying office building name, street address and room number. Create object tables EMP_TAB, DEPT_TAB and OFFICE_TAB that contain objects of typesemp_t, dept_tandoffice_t. Populate your tables by selecting data from tables EMP and DEPT in you demo schema and by plain inserts and updates where new data are needed. Using navigation through references create a result set presenting:

a) ename, empno, and location where employees work.

Extend you query to display

b) empno, ename, location, office_building_name, room_number.

Extend your query to display

c) Empno, manager's empno, ename, manager's ename, location of the employee and location of the manager