Execution time calculation issue

Question

Hi,
I have a proceudre which update the tables data and it will capture the execution time for each and every table.
For that i am using below procedure and its giving incorrect values. i.e., its giving end_time<start_time
PFB code(Line nos 25,26,33,73,7679,80 code for exeution time calculation) and output.
1 CREATE OR REPLACE PROCEDURE my_proc
2 IS
3 CURSOR c
4 IS
5 SELECT tablename, TYPE
6 FROM table_list;
7
8 TYPE emp_record IS RECORD (
9 empkey tab1.pkey%TYPE,
10 rid ROWID,
11 ID tab_join.ID%TYPE,
12 dt tab_join.dt%TYPE
13 );
14
15 TYPE emp_type IS TABLE OF emp_record
16 INDEX BY BINARY_INTEGER;
17
18 v_emp emp_type;
19
20 TYPE emp_type_rowid IS TABLE OF ROWID
21 INDEX BY BINARY_INTEGER;
22 tab_no Number:=0;
23 emp_rowid emp_type_rowid;
24 r_cur sys_refcursor;
25 v_start_time TIMESTAMP; /** Added for time calculation*/
26 v_end_time TIMESTAMP; /** Added for time calculation*/
27 string1 VARCHAR2 (1000) := 'SELECT b.empkey, b.ROWID rid, a.id id, a.dt dt FROM emp_base a,';
28 string2 VARCHAR2 (1000) := ' b WHERE a.empkey = b.empkey';
29 rowcnt Number;
30BEGIN
31 FOR c1 IN c
32 LOOP
33 tab_no:=tab_no+1;
34 v_start_time := SYSTIMESTAMP; /** Added for time calculation*/
35 BEGIN
36 string_d := string1 || c1.tablename || string2;
37
38 OPEN r_cur FOR string_d;
39
40 LOOP
41 FETCH r_cur
42 BULK COLLECT INTO v_emp LIMIT 50000;
43
44 IF v_emp.COUNT > 0
45 THEN
46 FOR j IN v_emp.FIRST .. v_emp.LAST
47 LOOP
48 emp_rowid (j) := v_emp (j).rid;
49 END LOOP;
50
51 upd_string := ' UPDATE ' || c1.tablename || ' SET id = ' || v_emp (1).ID || 'WHERE ROWID = :emp_rowid';
52 FORALL i IN emp_rowid.FIRST .. emp_rowid.LAST
53 EXECUTE IMMEDIATE upd_string
54 USING emp_rowid (i);
55 rowcnt := rowcnt + emp_rowid.COUNT;
56 END IF;
57
58 EXIT WHEN v_emp.COUNT < 50000;
59 v_emp.DELETE;
60 emp_rowid.DELETE;
61 END LOOP;
62
63 v_emp.DELETE;
64 emp_rowid.DELETE;
65
66 CLOSE r_cur;
67 EXCEPTION
68 WHEN OTHERS
69 THEN
70 DBMS_OUTPUT.put_line (SQLERRM);
71 END;
72
73 v_end_time := SYSTIMESTAMP; /** Added for time calculation*/
74
75 INSERT INTO exec_time
76 VALUES (tab_no||' '||c1.tablename, v_start_time, v_end_time, v_end_time - v_start_time, rowcnt); /** Added for time calculation*/
77
78 COMMIT;
79 v_start_time := NULL; /** Added for time calculation*/
80 v_end_time := NULL; /** Added for time calculation*/
81 rowcnt := 0;
82 END LOOP;
83END;
Output :
TableName: exec_time
"TABLE_NAME"      "START_TIME"     "END_TIME"      "EXCUTION_TIME"      "NO_OF_RECORDS_PROCESSED"
TAB7      5/29/2013 10:52:23.000000 AM      5/29/2013 10:52:24.000000 AM      +00 00:00:00.521707      773
TAB5      5/29/2013 10:52:18.000000 AM      5/29/2013 10:52:15.000000 AM      -00 00:00:03.381468      56525
TAB6      5/29/2013 10:52:15.000000 AM      5/29/2013 10:52:23.000000 AM      +00 00:00:08.624420      49078
TAB2      5/29/2013 10:51:54.000000 AM      5/29/2013 10:51:42.000000 AM      -00 00:00:11.932558      529
TAB4      5/29/2013 10:51:47.000000 AM      5/29/2013 10:52:18.000000 AM      +00 00:00:31.208966      308670
TAB1      5/29/2013 10:51:45.000000 AM      5/29/2013 10:51:54.000000 AM      +00 00:00:09.124238      65921
TAB3      5/29/2013 10:51:42.000000 AM      5/29/2013 10:51:47.000000 AM      +00 00:00:04.502432      12118
Issue: I am getting execution time in negitive values because end_time<start_time coming.
Please suggest me how to resolve this.
Thanks.

Answer 1

Welcome to the forum!!
Please read {message:id=9360002} from the FAQ to know the list of details (WHAT and HOW) you need to specify when asking a question.
I primarily hate 3 things in your code
1. The way you have used BULK update which is totally unnecessary
2. COMMIT inside LOOP
3. The use of WHEN OTHERS exception.
Your code can be simplified like this
create or replace procedure my_proc
is
   v_start_time timestamp;
   v_end_time   timestamp;
   v_rowcnt     integer;
begin
   for c1 in (
                 select rownum tab_no
                      , tablename
                      , type
                   from table_list
   loop
      sql_string := q'[
                              merge into #tablename# a
                              using (
                                      select id, dt
                                        from emp_base
                                    ) b
                                 on (
                                      a.empkey = b.empkey
                                when matched then
                                    update set a.id = b.id;
      sql_string := replace(sql_string, '#tablename#', c1.tablename);
      v_start_time := systimestamp;
      execute immediate sql_string;
      v_end_time   := systimestamp;
      v_rowcnt     := sql%rowcount;
      insert into exec_time
           values
                c1.tab_no || ' ' || c1.tablename
              , v_start_time
              , v_end_time
              , v_end_time - v_start_time
              , v_rowcnt
   end loop;
   commit;
end; In the INSERT statement on the table EXEC_TIME try to include the column list.
NOTE: The above code is untested.