*Dynamic* Table Name in From Clause with input from cursor

Question

Hello
I have a cursor say...
select table_name from dba_tables where <blah>
The result is
row1:: emp
rwo2:: emp_1 ---> Both the tables have same structure and entirely different data... please dont ask why... that's the way it is and we cant change it..
Now we need to run an Insert...
insert into tableX (col1,col2,...) select a,b,... from <o/p of the cursor> where <blah> ...
Note: The table name changes and it the cursor can o/p emp,emp_a and emp_b.
Am looking to do it parallel instead of doing it serially and with best performance ....no sql injection issues.
By parallel i mean
insert into tableX (col1,col2,...) select a,b,... from emp where <blah>
and insert into tableX (col1,col2,...) select a,b,... from emp_1 where <blah> statements to fire parallel/at the same time to the database. If you can share procedure if you guys already have with you.. is really appreciated
Thanks a lot for your time....
Edited by: user007009 on Apr 27, 2013 8:33 PM

Answer 1

Hello thanks for your time..
I tried to implement the chunk by sql parallel execution approach and it took 3.1 seconds to complete.. while the SP took around 0.042 seconds and the parallel process didn't throwed any errors and it didn't insert any data either... I am not sure what I am doing wrong... can you please let me know your thoughts...
Sample Data Creation::::::::::::::*
drop table table_ASERCARE purge;
drop table table_MEDCARE purge;
DROP TABLE TABLE_XYCARE PURGE;
DROP TABLE TABLE_TIME PURGE;
DROP TABLE TABLE_LOCATION PURGE;
drop table table_group purge;
drop table tablex purge;
-- select distinct TABLE_NAME from ALL_TAB_COLS where TABLE_NAME like 'EMP%';
create table table_asercare (time number(30), location_number number(5), value number(5),catg_id number(5));
insert into table_asercare values  (20110111, 01, 55, 1200);
insert into table_asercare values  (20110131, 01, 31, 1223);
insert into table_asercare values  (20120131, 15, 24,1224);
insert into table_ASERCARE values  (20130131, 03, 555,1200);
-- Truncate table table_MEDCARE
create table table_medcare (time number(30), location_number number(5), value number(5),catg_id number(5));
insert into table_medcare values  (20110113, 01, 23, 1200);
insert into table_medcare values  (20110128, 02, 78, 1223);
insert into table_medcare values  (20110130, 03, 100, 1224);
insert into table_medcare values  (20120111, 04, 57, 1200);
insert into table_medcare values  (20120221, 05, 64, 1223);
insert into table_MEDCARE values  (20130321, 15, 48, 1224);
create table table_xycare (time number(30), location_number number(5), value number(5),catg_id number(5));
insert into table_xycare values  (20100113, 01, 99, 1200);
insert into table_xycare values  (20110128, 02, 90, 1223);
insert into table_XYCARE values  (20130128, 03, 24, 1224);
create table table_LOCATION ( LOCATION_NUMBER number(5), LOCATION_NAME varchar2(50));
insert into table_LOCATION values  (01, 'atlanta1');
insert into table_LOCATION values  (02, 'atlanta2');
insert into table_LOCATION values  (03, 'atlanta3');
insert into table_LOCATION values  (04, 'atlanta4');
insert into table_LOCATION values  (05, 'atlanta5');
insert into table_location values  (15, 'atlanta15');
create table table_category (catg_id number(5), catg_name varchar2(30));
insert into table_category values (1200, 'EMS');
insert into table_category values (1223, 'LJM');
insert into table_category values (1224, 'LIO');
create table table_TIME (YEAR_MONTH_DATE number(30), YEAR_VAL number(4), MONTH_VAL number(2),DATE_VAL number(2));
insert into table_TIME values  (20110111, 2011, 01,11 );
insert into table_TIME values  (20110131, 2011, 01,31);
insert into table_TIME values  (20120131, 2012, 01,31);
insert into table_TIME values  (20130131, 2013, 01,31);
insert into table_TIME values  (20110128, 2011, 01,28 );
insert into table_TIME values  (20110130, 2011, 01,30 );
insert into table_TIME values  (20120111, 2012, 01,11 );
insert into table_TIME values  (20120221, 2012, 02,21 );
insert into table_TIME values  (20130321, 2013, 03,21 );
insert into table_TIME values  (20100113, 2010, 01,13 );
insert into table_TIME values  (20130128, 2013, 01,28 );
--Truncate table table_group
CREATE TABLE table_group (group_key number,table_name VARCHAR2(30), group_name VARCHAR2(30), catg_name varchar2(30));
insert into table_group values (1,'table_ASERCARE', 'GROUP_ONE','EMS');
insert into table_group values (2,'table_MEDCARE', 'GROUP_ONE','LJM');
INSERT INTO TABLE_GROUP VALUES (3,'table_XYCARE', 'GROUP_TWO','LIO');
create table TABLEX (YEAR_VAL number(4) ,LOCATION_NAME varchar2(50),tablename VARCHAR2(30), cnt number ); --> Proc data will be inserted into this...
Stored Procedure++++++++_
CREATE OR REPLACE
PROCEDURE ABC(
    GROUP_NAME_IN IN VARCHAR2 )
is
type c1 is ref cursor;
    sql_stmt VARCHAR2(200);
    v_sql    VARCHAR2(30000);
    c1_cv c1;
    table_name_f VARCHAR2(30);
    c1_rec TABLE_GROUP%rowtype;
  BEGIN
    SQL_STMT := 'SELECT * FROM TABLE_GROUP WHERE GROUP_NAME = :i';
    OPEN c1_cv FOR SQL_STMT USING GROUP_NAME_IN ;
    loop
      fetch c1_cv  INTO c1_rec;
    exit when c1_cv%notfound;
--    forall i in c1_rec.FIRST ..c1_rec.last loop
    table_name_f := c1_rec.table_name;
--      END LOOP;
   EXECUTE immediate
   'INSERT  INTO tablex (YEAR_VAL,LOCATION_NAME, tablename, cnt)
SELECT
t.YEAR_VAL,l.location_name, :table_name, count(*) as cnt
FROM '
    ||table_name_f||
    ' variable_table
,table_time t
, table_location l
,table_group g
,table_category ctg
WHERE t.year_month_date = variable_table.TIME
and variable_table.location_number = l.location_number
and ctg.catg_id = variable_table.catg_id
--and ctg.catg_name = g.catg_name
GROUP BY t.YEAR_VAL,l.location_name,g.catg_name' USING table_name_f;
    --dbms_output.put_line ( 'The SQL is'|| v_sql);
    COMMIT;
    --dbms_output.put_line ( c1_rec.table_name||','||c1_rec.group_name );
    --dbms_output.put_line ( 'The table name is '|| c1_rec.table_name );
  end loop;
    CLOSE c1_cv;
  --null;
END ABC;
Parallel Execution Code++++++++++_
begin
begin
DBMS_PARALLEL_EXECUTE.DROP_TASK(task_name => 'TASK_NAME');
exception when others then null;
end;
DBMS_PARALLEL_EXECUTE.CREATE_TASK(task_name => 'TASK_NAME');
DBMS_PARALLEL_EXECUTE.CREATE_CHUNKS_BY_SQL(task_name => 'TASK_NAME', sql_stmt =>'select distinct group_key, group_key from table_group', by_rowid => false);
end;
begin
DBMS_PARALLEL_EXECUTE.RUN_TASK (task_name => 'TASK_NAME',
sql_stmt =>'declare
s varchar2(16000); vstart_id number := :start_id; vend_id number:= :end_id;
table_name varchar2(30);
begin
select table_name into table_name from group_table where group_key=vstart_id;
s:=''INSERT  INTO tablex (YEAR_VAL,LOCATION_NAME, tablename, cnt)
SELECT
t.YEAR_VAL,l.location_name, :table_name, count(*) as cnt
FROM ''||table_name||'' variable_table
,table_time t
, table_location l
,table_group g
,table_category ctg
WHERE t.year_month_date = variable_table.TIME
and variable_table.location_number = l.location_number
and ctg.catg_id = variable_table.catg_id
and ctg.catg_name = g.catg_name
and g.group_key =:vstart_id
GROUP BY t.YEAR_VAL,l.location_name,g.catg_name'';
execute immediate s using vstart_id;
commit;
end;',
language_flag => DBMS_SQL.NATIVE, parallel_level => 2 );
end;
/ thanks in advance for your time.
Edited by: user007009 on Apr 28, 2013 12:25 PM