我有一个带有不同子句的查询：
SELECT -- /*+ first_rows */
distinct a.sub_id, b.status,
pkg_sp_subbrief.get_sub_typ (a.sub_id) sub_type,
c.svc_provider_nm, fn_sp_get_svc_plan (a.sub_id) svc_plan,
pkg_sp_subbrief.get_sub_contact_parm
(a.sub_id,
'contact.name.salutation'
) salutation,
pkg_sp_subbrief.get_sub_contact_parm
(a.sub_id,
'first_name'
) first_name,
pkg_sp_subbrief.get_sub_contact_parm
(a.sub_id,
'contact.name.middle'
) middle_name,
pkg_sp_subbrief.get_sub_contact_parm
(a.sub_id,
'last_name'
) last_name,
pkg_sp_subbrief.get_sub_parm (a.sub_id, 'company_name') company_name,
pkg_sp_subbrief.get_sub_parm (a.sub_id, 'itc_account') itc_accout,
pkg_sp_subbrief.get_sub_contact_parm
(a.sub_id,
'phones.home.number'
) phone_number,
pkg_sp_subbrief.get_location_parm
(a.sub_id,
'address_1'
) addr_home_address,
pkg_sp_subbrief.get_location_parm
(a.sub_id,
'city'
) addr_home_city,
pkg_sp_subbrief.get_location_parm
(a.sub_id,
'prov'
) addr_home_prov,
pkg_sp_subbrief.get_location_parm
(a.sub_id,
'postal_cd'
) addr_home_postal_code,
pkg_sp_subbrief.get_location_parm
(a.sub_id,
'country'
) addr_home_country,
e.val cm_mta_mac, ' ' telephone_number,
pkg_sp_subbrief.get_subsvc_parm_first (a.sub_id,
3374
) alpha_tag,
NVL (j.voipdn1, ' ') voip_dn1,
NVL (j.mtavoiceport, ' ') mta_voice_port
FROM svc_provider c,
ref_status b,
sub a,
sub_svc d,
sub_svc_parm e,
(SELECT f.sub_id, g.val voipdn1, i.val mtavoiceport
FROM sub_svc f, sub_svc_parm g, sub_svc_parm i
WHERE f.svc_id = SvcId('smp_dial_tone_access')
AND f.sub_svc_status_id ! = 29
AND f.sub_svc_id = g.sub_svc_id
AND g.parm_id = get_cgo_parm_id('voip_dn1', GET_CLASS_ID('SubSvcSpec'), SvcID('smp_dial_tone_access'))
AND f.sub_svc_id = i.sub_svc_id
AND i.parm_id = 20410) j
WHERE a.svc_provider_id = c.svc_provider_id
AND a.sub_status_id = b.status_id
AND a.sub_id = d.sub_id
AND d.sub_svc_id = e.sub_svc_id
AND (e.parm_id = 1254 OR e.parm_id = 20249)
AND d.sub_svc_status_id != 29
AND a.sub_status_id != 9
AND a.sub_id = j.sub_id(+);
此查询返回 10,146 行，执行时间几乎为 135 秒
对此的解释计划是：
Execution Plan
----------------------------------------------------------
Plan hash value: 2622307916
-----------------------------------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes |TempSpc| Cost (%CPU)| Time |
-----------------------------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 10409 | 1118K| | 2540 (4)| 00:00:31 |
| 1 | HASH UNIQUE | | 10409 | 1118K| 1240K| 2540 (4)| 00:00:31 |
|* 2 | HASH JOIN RIGHT OUTER | | 10409 | 1118K| | 2279 (4)| 00:00:28 |
| 3 | VIEW | | 899 | 23374 | | 1340 (6)| 00:00:17 |
|* 4 | HASH JOIN | | 899 | 53940 | | 1340 (6)| 00:00:17 |
|* 5 | HASH JOIN | | 885 | 35400 | | 918 (8)| 00:00:12 |
|* 6 | TABLE ACCESS BY INDEX ROWID| SUB_SVC | 877 | 17540 | | 434 (0)| 00:00:06 |
|* 7 | INDEX RANGE SCAN | SUB_SVC_IX2 | 951 | | | 3 (0)| 00:00:01 |
|* 8 | TABLE ACCESS FULL | SUB_SVC_PARM | 1770 | 35400 | | 483 (14)| 00:00:06 |
|* 9 | TABLE ACCESS FULL | SUB_SVC_PARM | 2632 | 52640 | | 422 (2)| 00:00:06 |
|* 10 | HASH JOIN | | 10409 | 853K| | 939 (2)| 00:00:12 |
|* 11 | TABLE ACCESS FULL | REF_STATUS | 95 | 2280 | | 3 (0)| 00:00:01 |
|* 12 | HASH JOIN | | 10409 | 609K| | 935 (2)| 00:00:12 |
| 13 | VIEW | index$_join$_001 | 49 | 588 | | 3 (34)| 00:00:01 |
|* 14 | HASH JOIN | | | | | | |
| 15 | INDEX FAST FULL SCAN | SVC_PROVIDER_PK | 49 | 588 | | 1 (0)| 00:00:01 |
| 16 | INDEX FAST FULL SCAN | SVC_PROVIDER_UK1 | 49 | 588 | | 1 (0)| 00:00:01 |
|* 17 | HASH JOIN | | 10409 | 487K| | 932 (2)| 00:00:12 |
|* 18 | TABLE ACCESS FULL | SUB | 8777 | 111K| | 53 (0)| 00:00:01 |
|* 19 | HASH JOIN | | 10607 | 362K| | 878 (2)| 00:00:11 |
|* 20 | TABLE ACCESS FULL | SUB_SVC_PARM | 10607 | 207K| | 423 (2)| 00:00:06 |
|* 21 | TABLE ACCESS FULL | SUB_SVC | 90284 | 1322K| | 454 (1)| 00:00:06 |
-----------------------------------------------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
2 - access("A"."SUB_ID"="J"."SUB_ID"(+))
4 - access("F"."SUB_SVC_ID"="I"."SUB_SVC_ID")
5 - access("F"."SUB_SVC_ID"="G"."SUB_SVC_ID")
6 - filter("F"."SUB_SVC_STATUS_ID"<>29)
7 - access("F"."SVC_ID"="SVCID"('smp_dial_tone_access'))
8 - filter("G"."PARM_ID"="GET_CGO_PARM_ID"('voip_dn1',"GET_CLASS_ID" ('SubSvcSpec'),"SVCID"('smp_dial_tone_access')))
9 - filter("I"."PARM_ID"=20410)
10 - access("A"."SUB_STATUS_ID"="B"."STATUS_ID")
11 - filter("B"."STATUS_ID"<>9)
12 - access("A"."SVC_PROVIDER_ID"="C"."SVC_PROVIDER_ID")
14 - access(ROWID=ROWID)
17 - access("A"."SUB_ID"="D"."SUB_ID")
18 - filter("A"."SUB_STATUS_ID"<>9)
19 - access("D"."SUB_SVC_ID"="E"."SUB_SVC_ID")
20 - filter("E"."PARM_ID"=1254 OR "E"."PARM_ID"=20249)
21 - filter("D"."SUB_SVC_STATUS_ID"<>29)
Statistics
----------------------------------------------------------
470461 recursive calls
0 db block gets
13591783 consistent gets
0 physical reads
0 redo size
1272441 bytes sent via SQL*Net to client
7960 bytes received via SQL*Net from client
678 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
10146 rows processed
当我从查询中删除 distinct 子句时，它会在 4 秒内执行但 QUERY RETURNS 10163 行，这意味着它也会返回重复的行。
这是没有 distinct 子句的执行计划：
Execution Plan
----------------------------------------------------------
Plan hash value: 3514824003
---------------------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
----------------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 10409 | 3608K| 2279 (4)| 00:00:28 |
|* 1 | HASH JOIN RIGHT OUTER | | 10409 | 3608K| 2279 (4)| 00:00:28 |
| 2 | VIEW | | 899 | 237K| 1340 (6)| 00:00:17 |
|* 3 | HASH JOIN | | 899 | 53940 | 1340 (6)| 00:00:17 |
|* 4 | HASH JOIN | | 885 | 35400 | 918 (8)| 00:00:12 |
|* 5 | TABLE ACCESS BY INDEX ROWID| SUB_SVC | 877 | 17540 | 434 (0)| 00:00:06 |
|* 6 | INDEX RANGE SCAN | SUB_SVC_IX2 | 951 | | 3 (0)| 00:00:01 |
|* 7 | TABLE ACCESS FULL | SUB_SVC_PARM | 1770 | 35400 | 483 (14)| 00:00:06 |
|* 8 | TABLE ACCESS FULL | SUB_SVC_PARM | 2632 | 52640 | 422 (2)| 00:00:06 |
|* 9 | HASH JOIN | | 10409 | 853K| 939 (2)| 00:00:12 |
|* 10 | TABLE ACCESS FULL | REF_STATUS | 95 | 2280 | 3 (0)| 00:00:01 |
|* 11 | HASH JOIN | | 10409 | 609K| 935 (2)| 00:00:12 |
| 12 | VIEW | index$_join$_001 | 49 | 588 | 3 (34)| 00:00:01 |
|* 13 | HASH JOIN | | | | | |
| 14 | INDEX FAST FULL SCAN | SVC_PROVIDER_PK | 49 | 588 | 1 (0)| 00:00:01 |
| 15 | INDEX FAST FULL SCAN | SVC_PROVIDER_UK1 | 49 | 588 | 1 (0)| 00:00:01 |
|* 16 | HASH JOIN | | 10409 | 487K| 932 (2)| 00:00:12 |
|* 17 | TABLE ACCESS FULL | SUB | 8777 | 111K| 53 (0)| 00:00:01 |
|* 18 | HASH JOIN | | 10607 | 362K| 878 (2)| 00:00:11 |
|* 19 | TABLE ACCESS FULL | SUB_SVC_PARM | 10607 | 207K| 423 (2)| 00:00:06 |
|* 20 | TABLE ACCESS FULL | SUB_SVC | 90284 | 1322K| 454 (1)| 00:00:06 |
----------------------------------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
1 - access("A"."SUB_ID"="J"."SUB_ID"(+))
3 - access("F"."SUB_SVC_ID"="I"."SUB_SVC_ID")
4 - access("F"."SUB_SVC_ID"="G"."SUB_SVC_ID")
5 - filter("F"."SUB_SVC_STATUS_ID"<>29)
6 - access("F"."SVC_ID"="SVCID"('smp_dial_tone_access'))
7 - filter("G"."PARM_ID"="GET_CGO_PARM_ID"('voip_dn1',"GET_CLASS_ID" ('SubSvcSpec'),"SVCID"('smp_dial_tone_access')))
8 - filter("I"."PARM_ID"=20410)
9 - access("A"."SUB_STATUS_ID"="B"."STATUS_ID")
10 - filter("B"."STATUS_ID"<>9)
11 - access("A"."SVC_PROVIDER_ID"="C"."SVC_PROVIDER_ID")
13 - access(ROWID=ROWID)
16 - access("A"."SUB_ID"="D"."SUB_ID")
17 - filter("A"."SUB_STATUS_ID"<>9)
18 - access("D"."SUB_SVC_ID"="E"."SUB_SVC_ID")
19 - filter("E"."PARM_ID"=1254 OR "E"."PARM_ID"=20249)
20 - filter("D"."SUB_SVC_STATUS_ID"<>29)
Statistics
----------------------------------------------------------
470461 recursive calls
0 db block gets
13592455 consistent gets
0 physical reads
0 redo size
1168343 bytes sent via SQL*Net to client
7971 bytes received via SQL*Net from client
679 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
10163 rows processed
因此，我正在寻找 distinct 子句的任何替代方法来调整此查询。
我的数据库版本是：
Oracle Database 11g 企业版 11.2.0.3.0 - 64 位生产