How can i execute code faster by using PLSQL - oracle

Question

----- My code is taking so much time to execute .it takes 1074 seconds to execute. Can someone tell me any way so that I can execute more faster--------
set serveroutput on;
declare
table_or_view_does_not_exist exception;
pragma exception_init(table_or_view_does_not_exist,-00942);
d_table varchar2(200);
q_table varchar2(200);
r_emp SYS.ODCINUMBERLIST := SYS.ODCINUMBERLIST();
type t_list is table of all_tab_columns%rowtype index by PLS_INTEGER;
v_array t_list;
begin
begin
d_table:='drop table subs_profile_spcl_char PURGE';
execute immediate d_table;
exception
when table_or_view_does_not_exist then
null;
end;
dbms_output.put_line('Table has been dropped');
q_table:='create table subs_profile_spcl_char
(column_name varchar2(50),
spcl_char_count Number)';
execute immediate q_table;
dbms_output.put_line('Table has been created');
dbms_output.enable;
select /*parallel(14)*/ * bulk collect into v_array from all_tab_columns where table_name='SUBSCRIBER_PROFILE' and OWNER='MIG';
for i in 1..v_array.count() loop
r_emp.extend;
EXECUTE IMMEDIATE
'select /*parallel(16)*/ count(*) from '||v_array(i).table_name||' where not regexp_like ('||v_array(i).column_name||',''[A-za-z0-9.]'')'
into r_emp(i);
if r_emp(i)<>0 then
dbms_output.put_line(v_array(i).column_name||'------------>>>>'||r_emp(i));
execute immediate 'insert into subs_profile_spcl_char values (:param1,:param2)' using v_array(i).column_name,r_emp(i);
end if;
end loop;
end;

Answer 1

The way I see it, a few objections.
you shouldn't drop/create table within PL/SQL; that's just bad practice. Create table at SQL level, then remove its contents (if you have to) in a procedure (truncate is faster than delete, but is irreversible. As you actually dropped the table, I'd say that you can use it)
target table is wrongly created anyway; knowing only the column name is far from enough - you should be storing owner and table name as well
it seems that you're looking for columns that contain "special characters" (i.e. not alphanumerics nor dots); in that case, modify regular expression
no need to scan all owners - SYS, SYSTEM, CTXSYS, possible APEX_ users most probably aren't interesting in what you're doing so - remove them. Remove other owners as well, if you want.
no need to scan all columns - numbers and dates can't contain special characters - filter only CHAR datatype family columns
no need to use r_emp collection. Fetch the count into a scalar variable (l_cnt in my example)
parallel "hint" is wrongly used. The way you put it, it is just a comment, not a hint. Hint looks like e.g. select /*+ parallel */ (you're missing a plus sign)
dbms_output takes resources; remove it if you don't need it (you don't; the result is anyway stored into the table)
insert into the target table doesn't require dynamic SQL so - switch to an ordinary insert
OK, here you go, here's what you might try to do.
(re)create the target table at SQL level:
SQL> DROP TABLE subs_profile_spcl_char;
Table dropped.
SQL> CREATE TABLE subs_profile_spcl_char
2 (
3 owner VARCHAR2 (30),
4 table_name VARCHAR2 (30),
5 column_name VARCHAR2 (30),
6 spcl_char_count NUMBER
7 );
Table created.
PL/SQL code:
SQL> set timing on
SQL>
SQL> DECLARE
2 TYPE t_list_rec IS RECORD
3 (
4 owner all_tab_columns.owner%TYPE,
5 table_name all_tab_columns.table_name%TYPE,
6 column_name all_tab_columns.column_name%TYPE
7 );
8
9 TYPE t_list IS TABLE OF t_list_rec;
10
11 v_array t_list;
12 --
13 l_cnt NUMBER;
14 BEGIN
15 EXECUTE IMMEDIATE 'truncate table subs_profile_spcl_char';
16
17 SELECT owner, table_name, column_name
18 BULK COLLECT INTO v_array
19 FROM all_tab_columns
20 WHERE owner NOT LIKE '%SYS%'
21 AND owner NOT LIKE 'APEX%'
22 AND data_type LIKE '%CHAR%';
23
24 FOR i IN 1 .. v_array.COUNT ()
25 LOOP
26 BEGIN
27 EXECUTE IMMEDIATE 'select count(*) from '
28 || v_array (i).owner
29 || '.'
30 || v_array (i).table_name
31 || ' where not regexp_like ('
32 || v_array (i).column_name
33 || ',''^[A-za-z0-9.]+$'')'
34 INTO l_cnt;
35 EXCEPTION
36 WHEN OTHERS
37 THEN
38 -- for tables you can't access
39 NULL;
40 END;
41
42 IF l_cnt > 0
43 THEN
44 INSERT INTO subs_profile_spcl_char
45 VALUES (v_array (i).owner,
46 v_array (i).table_name,
47 v_array (i).column_name,
48 l_cnt);
49 END IF;
50 END LOOP;
51 END;
52 /
PL/SQL procedure successfully completed.
Elapsed: 00:00:00.58
SQL> set timing off
It took 580 miliseconds (as opposed to your 1000 seconds).
Number of scanned columns:
SQL> SELECT COUNT (*)
2 FROM all_tab_columns
3 WHERE owner NOT LIKE '%SYS%'
4 AND owner NOT LIKE 'APEX%'
5 AND data_type LIKE '%CHAR%';
COUNT(*)
----------
172
Without filter:
SQL> SELECT COUNT (*)
2 FROM all_tab_columns;
COUNT(*)
----------
39697
SQL>
Why would you check 40.000 columns, if you can do that on 200 columns instead?
Final result:
SQL> SELECT *
2 FROM subs_profile_spcl_char
3 ORDER BY owner DESC, table_name, column_name;
OWNER TABLE_NAME COLUMN_NAME SPCL_CHAR_COUNT
-------------------- ------------------------- -------------------- ---------------
XDB PATH_VIEW PATH 137
XDB RESOURCE_VIEW ANY_PATH 137
SCOTT BONUS JOB 1
SCOTT DEPT LOC 1
SCOTT PRODUCTS PRODUCT_NAME 4
SCOTT SUBS_PROFILE_SPCL_CHAR COLUMN_NAME 18
SCOTT SUBS_PROFILE_SPCL_CHAR OWNER 2
SCOTT SUBS_PROFILE_SPCL_CHAR TABLE_NAME 24
ORDS_METADATA USER_ORDS_OBJECTS OBJECT_ALIAS 3
ORDS_METADATA USER_ORDS_OBJECTS PARSING_OBJECT 3
ORDDATA ORDDCM_DBRELEASE_DOCS DOC_TYPE 3
ORDDATA ORDDCM_DOCUMENT_TYPES DOC_TYPE 4
<snip>
29 rows selected.
SQL>