measure time of an sql statement in a procedure in plsql - oracle

Question

I must write a procedure which save the execute time of any sql-statement in a table.
The procedure is calling by exec measuresqltime('sql statement as string');
My idea is like this:
--declarations
timestart NUMBER;
BEGIN
dbms_output.enable;
timestart:=dbms_utility.get_time();
EXECUTE IMMEDIATE sql
COMMIT;
dbms_output.put_line(dbms_utility.get_time()-timestart);
-- save time
But it didn't work for me for a SELECT *... clause. (I think sql need a INTO-order)
Is there a way to execute any sql-atatements in a procedure?

Answer 1

If your SQL statement is a SELECT, you need to fetch from the cursor to have a meaningful measure of its execution time.
If you don't fetch from the cursor, you only measure the time spent in "parse" and "execution" phases, whereas much of the work is usually done in the "fetch" phase for SELECT statements.
You won't be able to fetch with EXECUTE IMMEDIATE or OPEN cursor FOR 'string' if you don't know the number of columns the actual statement will have. You will have to use the dynamic SQL package DBMS_SQL if the number/type of columns of the SELECT is unknown.
Here's an example:
SQL> CREATE OR REPLACE PROCEDURE demo(p_sql IN VARCHAR2) AS
2 l_cursor INTEGER;
3 l_dummy NUMBER;
4 timestart NUMBER;
5 BEGIN
6 dbms_output.enable;
7 timestart := dbms_utility.get_time();
8 l_cursor := dbms_sql.open_cursor;
9 dbms_sql.parse(l_cursor, p_sql, dbms_sql.native);
10 l_dummy := dbms_sql.execute(l_cursor);
11 LOOP
12 EXIT WHEN dbms_sql.fetch_rows(l_cursor) <= 0;
13 END LOOP;
14 dbms_sql.close_cursor(l_cursor);
15 dbms_output.put_line(dbms_utility.get_time() - timestart);
16 END;
17 /
Procedure created.
SQL> exec demo('SELECT * FROM dual CONNECT BY LEVEL <= 1e6');
744
PL/SQL procedure successfully completed.
Note that this will measure the time needed to fetch to the last row of the SELECT.

Answer 2

completing devosJava answered... avoid using it at dawn ;P
PROCEDURE MY_PROCEDURE IS
timeStart TIMESTAMP;
timeEnd TIMESTAMP;
timeSecond NUMBER
BEGIN
timeStart := SYSTIMESTAMP;
-- YOUR CODE HERE
timeEnd := SYSTIMESTAMP;
timeSecond :=((extract(hour from timeEnd)*3600)+(extract(minute from timeEnd)*60)+extract(second from timeEnd))-((extract(hour from timeStart)*3600)+(extract(minute from timeStart)*60)+extract(second from timeStart));
dbms_output.put_line('finished: '||timeSecond||' seconds');
END MY_PROC;

Answer 3

To calculate the duration for an execution time
PROCEDURE MY_PROCEDURE IS
timeStart TIMESTAMP;
timeEnd TIMESTAMP;
BEGIN
timeStart := SYSTIMESTAMP;
-- YOUR CODE HERE
timeEnd := SYSTIMESTAMP;
INSERT INTO PROC_RUNTIMES (PROC_NAME, START_TIME, END_TIME)
VALUES ('MY_PROCEDURE ', timeStart , timeEnd );
END MY_PROC;

Answer 4

INSERT INTO PROC_RUNTIMES (PROC_NAME, START_TIME, END_TIME)
VALUES ('PROC_NAME', TO_CHAR
(SYSDATE, 'DD/MM/YYYY HH24:MI:SS'),NULL );
Your query here;
INSERT INTO PROC_RUNTIMES (PROC_NAME, START_TIME, END_TIME)
VALUES ('PROC_NAME',NULL, TO_CHAR
(SYSDATE, 'DD/MM/YYYY HH24:MI:SS'));