Need to Rewrite Distinct query...

Question

Hi All,
Query A:
SELECT count(DISTINCT FIELD_SERVICE_REP) CNT1
  FROM SOP_SERVICE_REQUEST_JOB ssrj, sop_service_request ssr
WHERE TO_DATE('06/12/2006', 'mm/dd/yyyy') BETWEEN
       SSRJ.SCHEDULED_START_DATE AND SSRJ.SCHEDULED_END_DATE
       AND field_service_rep IS NOT NULL
       AND ssr.service_request_id = ssrj.service_request_id
Result of Query A:-
17 --> This is correct result
Query B:
SELECT FIELD_SERVICE_REP, count(FIELD_SERVICE_REP) CNT2
  FROM SOP_SERVICE_REQUEST_JOB ssrj, sop_service_request ssr
WHERE TO_DATE('06/12/2006', 'mm/dd/yyyy') BETWEEN
       SSRJ.SCHEDULED_START_DATE AND SSRJ.SCHEDULED_END_DATE
       AND field_service_rep IS NOT NULL
       AND ssr.service_request_id = ssrj.service_request_id
       GROUP BY ssrj.field_service_rep
Result of Query B:-
FIELD_SERVICE_REP      CNT2
1000036                  9
105005937          1
113001460          1
113001757          3
113002205          2
113002476          4
113003027          2
113003166          1
218012616          1
218012630          1
312003325          1
500916804          1
500935725          2
501026039          6
501154894          1
501243382          3
501248836          6I need to rewrite Query A in such a way that I get rid of DISTINCT as it is consuming a lot of time. I tried to group by in Query B and count but it is not giving same result as Query A (as expected..) so how can I rewrite Query A or Query B to get result of Query A (basically count unique field service reps.) as correct result is the one shown in Query A.
Pls. note that original query is very large and it runs on set of dates and hence DISTINCT is taking too much time
Thanks in advance to all for ur help..
JP

Answer 1

Some sample data:
DROP TABLE SOP_SERVICE_REQUEST;
CREATE TABLE SOP_SERVICE_REQUEST(service_request_id number(6,0));
INSERT
INTO SOP_SERVICE_REQUEST
VALUES(100);
INSERT
INTO SOP_SERVICE_REQUEST
VALUES(101);
INSERT
INTO SOP_SERVICE_REQUEST
VALUES(102);
INSERT
INTO SOP_SERVICE_REQUEST
VALUES(103);
INSERT
INTO SOP_SERVICE_REQUEST
VALUES(104);
DROP TABLE SOP_SERVICE_REQUEST_job;
CREATE TABLE SOP_SERVICE_REQUEST_job(service_request_id number(6,0), SCHEDULED_START_DATE date,SCHEDULED_END_DATE date,field_service_rep number(6,0));
INSERT
INTO SOP_SERVICE_REQUEST_job
VALUES(100, '10-jun-06', '16-jun-06', 200);
INSERT
INTO SOP_SERVICE_REQUEST_job
VALUES(101, '10-jun-06', '16-jun-06', 201);
INSERT
INTO SOP_SERVICE_REQUEST_job
VALUES(102, '10-jun-06', '16-jun-06', 201);
INSERT
INTO SOP_SERVICE_REQUEST_job
VALUES(103, '10-jun-06', '16-jun-06', 202);
INSERT
INTO SOP_SERVICE_REQUEST_job
VALUES(104, '10-jun-06', '16-jun-06', 201);
select * from sop_service_request
select * from sop_service_request_job
prompt Query A:
SELECT count(FIELD_SERVICE_REP) CNT1
FROM SOP_SERVICE_REQUEST_JOB ssrj, sop_service_request ssr
WHERE TO_DATE('06/12/2006', 'mm/dd/yyyy')
BETWEEN SSRJ.SCHEDULED_START_DATE AND SSRJ.SCHEDULED_END_DATE
AND field_service_rep IS NOT NULL
AND ssr.service_request_id = ssrj.service_request_id;
prompt Query B:
SELECT FIELD_SERVICE_REP, count(FIELD_SERVICE_REP) CNT2
FROM SOP_SERVICE_REQUEST_JOB ssrj, sop_service_request ssr
WHERE TO_DATE('06/12/2006', 'mm/dd/yyyy')
BETWEEN SSRJ.SCHEDULED_START_DATE AND SSRJ.SCHEDULED_END_DATE
AND field_service_rep IS NOT NULL
AND ssr.service_request_id = ssrj.service_request_id
GROUP BY ssrj.field_service_rep;
Output:
DROP TABLE SOP_SERVICE_REQUEST succeeded.
CREATE TABLE succeeded.
1 rows inserted
1 rows inserted
1 rows inserted
1 rows inserted
DROP TABLE SOP_SERVICE_REQUEST_job succeeded.
CREATE TABLE succeeded.
1 rows inserted
1 rows inserted
1 rows inserted
1 rows inserted
Query A:
CNT1
4
1 rows selected
Query B:
FIELD_SERVICE_REP CNT2
201 2
200 1
202 1
3 rows selected