Performance Tuning Query on Large Tables

Question

Hi All,
I am new to the forums and have a very specic use case which requires performance tuning, but there are some limitations on what changes I am actualy able to make to the underlying data. Essentially I have two tables which contain what should be identical data, but for reasons of a less than optimal operational nature, the datasets are different in a number of ways.
Essentially I am querying call record detail data. Table 1 (refered to in my test code as TIME_TEST) is what I want to consider the master data, or the "ultimate truth" if you will. Table one contains the CALLED_NUMBER which is always in a consistent format. It also contains the CALLED_DATE_TIME and DURATION (in seconds).
Table 2 (TIME_TEST_COMPARE) is a reconciliation table taken from a different source but there is no consistent unique identifiers or PK-FK relations. This table contains a wide array of differing CALLED_NUMBER formats, hugely different to that in the master table. There is also scope that the time stamp may be out by up to 30 seconds, crazy I know, but that's just the way it is and I have no control over the source of this data. Finally the duration (in seconds) can be out by up to 5 seconds +/-.
I want to create a join returning all of the master data and matching the master table to the reconciliation table on CALLED_NUMBER / CALL_DATE_TIME / DURATION. I have written the query which works from a logi perspective but it performs very badly (master table = 200,000 records, rec table = 6,000,000+ records). I am able to add partitions (currently the tables are partitioned by month of CALL_DATE_TIME) and can also apply indexes. I cannot make any changes at this time to the ETL process loading the data into these tables.
I paste below the create table and insert scripts to recreate my scenario & the query that I am using. Any practical suggestions for query / table optimisation would be greatly appreciated.
Kind regards
Mike
-------------- NOTE: ALL DATA HAS BEEN DE-SENSITISED
/* --- CODE TO CREATE AND POPULATE TEST TABLES ---- */
--CREATE MAIN "TIME_TEST" TABLE: THIS TABLE HOLDS CALLED NUMBERS IN A SPECIFIED/PRE-DEFINED FORMAT
CREATE TABLE TIME_TEST ( CALLED_NUMBER VARCHAR2(50 BYTE),
                                        CALLED_DATE_TIME DATE, DURATION NUMBER );
COMMIT;
-- CREATE THE COMPARISON TABLE "TIME_TEST_COMPARE": THIS TABLE HOLDS WHAT SHOULD BE (BUT ISN'T) IDENTICAL CALL DATA.
-- THE DATA CONTAINS DIFFERING NUMBER FORMATS, SLIGHTLY DIFFERENT CALL TIMES (ALLOW +/-60 SECONDS - THIS IS FOR A GOOD, ALBEIT UNHELPFUL, REASON)
-- AND DURATIONS (ALLOW +/- 5 SECS)                                        
CREATE TABLE TIME_TEST_COMPARE ( CALLED_NUMBER VARCHAR2(50 BYTE),
                                   CALLED_DATE_TIME DATE, DURATION NUMBER )                                        
COMMIT;
--CREATE INSERT DATA FOR THE MAIN TEST TIME TABLE
INSERT INTO TIME_TEST ( CALLED_NUMBER, CALLED_DATE_TIME,
DURATION ) VALUES (
'7721345675', TO_DATE( '11/09/2011 06:10:21 AM', 'MM/DD/YYYY HH:MI:SS AM'), 202);
INSERT INTO TIME_TEST ( CALLED_NUMBER, CALLED_DATE_TIME,
DURATION ) VALUES (
'7721345675', TO_DATE( '11/09/2011 08:10:21 AM', 'MM/DD/YYYY HH:MI:SS AM'), 19);
INSERT INTO TIME_TEST ( CALLED_NUMBER, CALLED_DATE_TIME,
DURATION ) VALUES (
'7721345675', TO_DATE( '11/09/2011 07:10:21 AM', 'MM/DD/YYYY HH:MI:SS AM'), 35);
INSERT INTO TIME_TEST ( CALLED_NUMBER, CALLED_DATE_TIME,
DURATION ) VALUES (
'7721345675', TO_DATE( '11/09/2011 09:10:21 AM', 'MM/DD/YYYY HH:MI:SS AM'), 30);
INSERT INTO TIME_TEST ( CALLED_NUMBER, CALLED_DATE_TIME,
DURATION ) VALUES (
'7721345675', TO_DATE( '11/09/2011 06:18:47 AM', 'MM/DD/YYYY HH:MI:SS AM'), 6);
INSERT INTO TIME_TEST ( CALLED_NUMBER, CALLED_DATE_TIME,
DURATION ) VALUES (
'7721345675', TO_DATE( '11/09/2011 06:20:21 AM', 'MM/DD/YYYY HH:MI:SS AM'), 20);
COMMIT;
-- CREATE INSERT DATA FOR THE TABLE WHICH NEEDS TO BE COMPARED:
INSERT INTO TIME_TEST_COMPARE ( CALLED_NUMBER, CALLED_DATE_TIME,
DURATION ) VALUES (
'7721345675', TO_DATE( '11/09/2011 06:10:51 AM', 'MM/DD/YYYY HH:MI:SS AM'), 200);
INSERT INTO TIME_TEST_COMPARE ( CALLED_NUMBER, CALLED_DATE_TIME,
DURATION ) VALUES (
'00447721345675', TO_DATE( '11/09/2011 08:10:59 AM', 'MM/DD/YYYY HH:MI:SS AM'), 21);
INSERT INTO TIME_TEST_COMPARE ( CALLED_NUMBER, CALLED_DATE_TIME,
DURATION ) VALUES (
'07721345675', TO_DATE( '11/09/2011 07:11:20 AM', 'MM/DD/YYYY HH:MI:SS AM'), 33);
INSERT INTO TIME_TEST_COMPARE ( CALLED_NUMBER, CALLED_DATE_TIME,
DURATION ) VALUES (
'[phone]', TO_DATE( '11/09/2011 09:10:01 AM', 'MM/DD/YYYY HH:MI:SS AM'), 33);
INSERT INTO TIME_TEST_COMPARE ( CALLED_NUMBER, CALLED_DATE_TIME,
DURATION ) VALUES (
'[phone]#181345', TO_DATE( '11/09/2011 06:18:35 AM', 'MM/DD/YYYY HH:MI:SS AM')
, 6);
INSERT INTO TIME_TEST_COMPARE ( CALLED_NUMBER, CALLED_DATE_TIME,
DURATION ) VALUES (
'004477213456759777799', TO_DATE( '11/09/2011 06:19:58 AM', 'MM/DD/YYYY HH:MI:SS AM')
, 17);
COMMIT;
/* --- QUERY TO UNDERTAKE MATCHING WHICH REQUIRES OPTIMISATION --------- */
SELECT MAIN.CALLED_NUMBER AS MAIN_CALLED_NUMBER, MAIN.CALLED_DATE_TIME AS MAIN_CALL_DATE_TIME, MAIN.DURATION AS MAIN_DURATION,
     COMPARE.CALLED_NUMBER AS COMPARE_CALLED_NUMBER,COMPARE.CALLED_DATE_TIME AS COMPARE_CALLED_DATE_TIME,
     COMPARE.DURATION COMPARE_DURATION     
FROM
SELECT CALLED_NUMBER, CALLED_DATE_TIME, DURATION
FROM TIME_TEST
) MAIN
LEFT JOIN
SELECT CALLED_NUMBER, CALLED_DATE_TIME, DURATION
FROM TIME_TEST_COMPARE
) COMPARE
ON INSTR(COMPARE.CALLED_NUMBER,MAIN.CALLED_NUMBER)<> 0
AND MAIN.CALLED_DATE_TIME BETWEEN COMPARE.CALLED_DATE_TIME-(60/86400) AND COMPARE.CALLED_DATE_TIME+(60/86400)
AND MAIN.DURATION BETWEEN MAIN.DURATION-(5/86400) AND MAIN.DURATION+(5/86400);

Answer 1

What does your execution plan look like?