Guide me to tune the query

Question

Hi All,
I need to tune the query which is taking more than 1 hour to execute over 8 Lakhs of record.
SQL> explain plan for SELECT C.aci_cust_code      cust_code,
2 C.aci_cust_name cust_name,
3      R.NAME ruledefination,
4 B.RULECODE ALERTS,
5 A.custom1 tran_id,
6 TD_get_value('AMLTRANTYPE', RTRIM(A.custom17)) trantype,
7 A.CUSTOM18 tran_nature,
8 A.custom25 tran_date,
9 A.messageno messageno,
10 TD_get_value('AMLTRANSTATUS', A.status) msgstatus,
11 D.acai_acct_type acct_type,
12 A.custom19 acct_number,
13 A.CURRENCY CURRENCY,
14 A.priorityamount amount,
15 A.operator USERNAME,
16 A.msgdb_id msgdb_id,
17 A.msg_mode_in msg_mode_in
18 FROM MSGDB A,
19 MSGALERTS B,
20 AML_CUST_INFO C,
21      AML_CUST_ACC_INFO D,
22 RULETBL2 R,
23           (SELECT tdkey FROM tabledetails WHERE tdidcode = 'AML-INCLUDEQ' ) amlqueues
24 WHERE A.msgdb_id = B.msgdb_id AND
25 A.queueid = amlqueues.tdkey AND
26           A.MSG_MODE_IN = 'AML-TRANS' AND
27 A.custom15 = C.aci_cust_code AND
28 A.CUSTOM19=D.ACAI_ACCT_NUMBER(+) AND
29 TO_CHAR(A.custom25,'YYYYMMDD') BETWEEN
30      TO_CHAR(TO_DATE('2011/01/01','YYYY/MM/DD'),'YYYYMMDD')
31 AND TO_CHAR(TO_DATE('2011/01/31','YYYY/MM/DD'),'YYYYMMDD')
32 AND B.RULECODE = R.RULECODE
33 ORDER BY A.custom25, msgdb_id,B.rulecode;
Explained.
PLAN_TABLE_OUTPUT
Plan hash value: 1081661146
| Id | Operation | Name | Rows | Bytes |TempSpc| Cost (%CPU)| Time |
| 0 | SELECT STATEMENT | | 173K| 30M| | 12697 (2)| 00:02:33 |
| 1 | SORT ORDER BY | | 173K| 30M| 66M| 12697 (2)| 00:02:33 |
|* 2 | HASH JOIN | | 173K| 30M| | 5580 (4)| 00:01:07 |
| 3 | VIEW | index$_join$_005 | 3395 | 81480 | | 42 (3)| 00:00:01 |
|* 4 | HASH JOIN | | | | | | |
| 5 | INDEX FAST FULL SCAN | IDX_RCODE | 3395 | 81480 | | 10 (0)| 00:00:01 |
| 6 | INDEX FAST FULL SCAN | SYS_C0040836 | 3395 | 81480 | | 31 (0)| 00:00:01 |
|* 7 | HASH JOIN | | 1737 | 276K| | 5534 (4)| 00:01:07 |
|* 8 | HASH JOIN | | 559 | 86645 | | 4575 (3)| 00:00:55 |
|* 9 | HASH JOIN OUTER | | 448 | 56000 | | 4463 (3)| 00:00:54 |
| 10 | NESTED LOOPS | | 448 | 47040 | | 4404 (3)| 00:00:53 |
|* 11 | TABLE ACCESS BY INDEX ROWID| MSGDB | 451 | 35178 | | 4403 (3)| 00:00:53 |
|* 12 | INDEX RANGE SCAN | I_MODEDATE | 2292 | | | 4323 (3)| 00:00:52 |
|* 13 | INDEX UNIQUE SCAN | PK_TABLEDETAIL | 1 | 27 | | 0 (0)| 00:00:01 |
| 14 | INDEX FAST FULL SCAN | ACC_NUMBER_TYPE | 58947 | 1151K| | 58 (4)| 00:00:01 |
| 15 | TABLE ACCESS FULL | AML_CUST_INFO | 18340 | 537K| | 111 (1)| 00:00:02 |
| 16 | TABLE ACCESS FULL | MSGALERTS | 868K| 6782K| | 944 (4)| 00:00:12 |
There is no index on RULECODE of MSGALERTS and RULETBL2 table.
Could yu guys guide me how to tune this query with or without creating any new index.
Thanks,

Answer 1

To emphasise what hoek has said regarding dates, NEVER compare dates with dates by converting them to strings (or numbers). By doing so, you remove vital information from the optimizer.
For example, what is the difference between "31st Dec 2010" and "1st Jan 2011"? Easy, they're dates, that's 1 day.
But what's the difference between "20101231" and "20110101"? Easy: 20110101 - 20101231 = 8870.
That makes the difference between the optimizer guessing 1 row or 8870 rows... a fairly big difference, I think you'll agree, which could well impact on the plan the optimizer chooses.
One other point - leaving the clause as dates gives:
AND    a.custom25 BETWEEN TO_DATE('2011/01/01', 'YYYY/MM/DD')
                      AND TO_DATE('2011/01/31', 'YYYY/MM/DD') which excludes any dates on 31st Jan 2011 except midnight, eg. 10am on 31st Jan 2011 won't be returned by your query.
If you're after rows for a given month, then you could do:
AND    trunc(a.custom25, 'mm') = TO_DATE('01/01/2011', 'dd/mm/yyyy')