问题现象

通过SPR日志发现 打开节点-后台任务日志节点sql调用严重。

通过nmc查看，后台线程耗时20s ，基本都卡在sql层面

一直在执行如下sql

select
    l.pk_workingtasklog
from
    pub_workingtasklog l
inner join
    pub_alertregistry r
        on l.pkregistry = r.pk_alertregistry
where
    l.tasktype in (
        1 , 2
    )
    and r.groupid in (
        '0001A210000000001JRQ' , 'GLOBLE00000000000000'
    )
order by
    l.endtime desc 

看下执行计划

1	Plan hash value: 2019149088
2	 
3	-------------------------------------------------------------------------------------------------------
4	| Id  | Operation                | Name               | Rows  | Bytes |TempSpc| Cost (%CPU)| Time     |
5	-------------------------------------------------------------------------------------------------------
6	|   0 | SELECT STATEMENT         |                    |   789K|    80M|       | 34015   (1)| 00:06:49 |
7	|   1 |  SORT ORDER BY           |                    |   789K|    80M|    90M| 34015   (1)| 00:06:49 |
8	|*  2 |   HASH JOIN              |                    |   789K|    80M|       | 14873   (1)| 00:02:59 |
9	|*  3 |    VIEW                  | index$_join$_002   |   100 |  4200 |       |     6  (17)| 00:00:01 |
10	|*  4 |     HASH JOIN            |                    |       |       |       |            |          |
11	|   5 |      INLIST ITERATOR     |                    |       |       |       |            |          |
12	|*  6 |       INDEX RANGE SCAN   | I_PUB_ALTRGS_2     |   100 |  4200 |       |     2   (0)| 00:00:01 |
13	|   7 |      INDEX FAST FULL SCAN| PK_PUB_ALERTREGIST |   100 |  4200 |       |     4   (0)| 00:00:01 |
14	|*  8 |    TABLE ACCESS FULL     | PUB_WORKINGTASKLOG |  1254K|    77M|       | 14858   (1)| 00:02:59 |
15	-------------------------------------------------------------------------------------------------------
16	 
17	Predicate Information (identified by operation id):
18	---------------------------------------------------
19	 
20	   2 - access("L"."PKREGISTRY"="R"."PK_ALERTREGISTRY")
21	   3 - filter("R"."GROUPID"='0001A210000000001JRQ' OR "R"."GROUPID"='GLOBLE00000000000000')
22	   4 - access(ROWID=ROWID)
23	   6 - access("R"."GROUPID"='0001A210000000001JRQ' OR "R"."GROUPID"='GLOBLE00000000000000')
24	   8 - filter("L"."TASKTYPE"=1 OR "L"."TASKTYPE"=2)

 问题分析

 走了全表扫描解决方案

create index i_PUB_WORKINGTASKLOG _1 on PUB_WORKINGTASKLOG (pkregistry,tasktype) tablespace nnc_index01 nologging parallel 4;
create index i_pub_alertregistry_1 on pub_alertregistry(pk_alertregistry,groupid) tablespace nnc_index01 nologging parallel 4;