惜分飞

出现如下错误(ORA-00001: unique constraint (PERFSTAT.STATS$SQL_SUMMARY_PK) violated)

Oracle9i Enterprise Edition Release 9.2.0.6.0 - 64bit Production
With the Partitioning option
JServer Release 9.2.0.6.0 - Production
ORACLE_HOME = /oracle9/app/product/9.2.0
System name:    AIX
Node name:      zwq_bill_1
Release:        1
Version:        6
Machine:        00F64FF34C00
Instance name: bill1
Redo thread mounted by this instance: 1
Oracle process number: 30
Unix process pid: 46531060, image: oracle@zwq_bill_1 (J000)

*** SESSION ID:(218.47085) 2012-04-02 19:30:45.561
*** 2012-04-02 19:30:45.561
ORA-12012: error on auto execute of job 1
ORA-00001: unique constraint (PERFSTAT.STATS$SQL_SUMMARY_PK) violated
ORA-06512: at "PERFSTAT.STATSPACK", line 1361
ORA-06512: at "PERFSTAT.STATSPACK", line 2471
ORA-06512: at "PERFSTAT.STATSPACK", line 91
ORA-06512: at line 1

这个是oracle的一个Bug 2784796,提供解决方法有
1.run the statspack at level 0
2.restart the instance
3.set cursor sharing to exact (probably not feasible)
4.禁用主键，创建合适非唯一index

ALTER TABLE PERFSTAT.STATS$SQL_SUMMARY MODIFY 
CONSTRAINT STATS$SQL_SUMMARY_PK DISABLE NOVALIDATE;

5.修改STATS$V_$SQLXS视图
分析思路如下:
1)根据主键冲突找到主键包含列(spctab.sql)

create table          STATS$SQL_SUMMARY
(snap_id              number(6)        not null
,dbid                 number           not null
,instance_number      number           not null
,text_subset          varchar2(31)     not null
,sql_text             varchar2(1000)
,sharable_mem         number
,sorts                number
,module               varchar2(64)
,loaded_versions      number
,fetches              number
,executions           number
,loads                number
,invalidations        number
,parse_calls          number
,disk_reads           number
,buffer_gets          number
,rows_processed       number
,command_type         number
,address              raw(8)
,hash_value           number
,version_count        number
,cpu_time             number
,elapsed_time         number
,outline_sid          number
,outline_category     varchar2(64)
,child_latch          number
--注意下面5列构成主键
,constraint STATS$SQL_SUMMARY_PK primary key
    (snap_id, dbid, instance_number, hash_value, text_subset)
 using index tablespace &&tablespace_name
   storage (initial 1m next 1m pctincrease 0)
,constraint STATS$SQL_SUMMARY_FK foreign key (snap_id, dbid, instance_number)
                references STATS$SNAPSHOT on delete cascade
)tablespace &&tablespace_name
storage (initial 1m next 1m pctincrease 0) pctfree 5 pctused 40;

2)找到该表插入数据(spcpkg.sql)

insert into stats$sql_summary
            ( snap_id
            , dbid
            , instance_number
            , text_subset
            , sharable_mem
            , sorts
            , module
            , loaded_versions
            , fetches
            , executions
            , loads
            , invalidations
            , parse_calls
            , disk_reads
            , buffer_gets
            , rows_processed
            , command_type
            , address
            , hash_value
            , version_count
            , cpu_time
            , elapsed_time
            , outline_sid
            , outline_category
            , child_latch
            )
       select l_snap_id
            , p_dbid
            , p_instance_number
            , substrb(sql_text,1,31)
            , sharable_mem
            , sorts
            , module
            , loaded_versions
            , fetches
            , executions
            , loads
            , invalidations
            , parse_calls
            , disk_reads
            , buffer_gets
            , rows_processed
            , command_type
            , address
            , hash_value
            , version_count
            , cpu_time
            , elapsed_time
            , outline_sid
            , outline_category
            , child_latch
         from stats$v$sqlxs
        where is_obsolete = 'N'
          and (   buffer_gets   > l_buffer_gets_th
               or disk_reads    > l_disk_reads_th
               or parse_calls   > l_parse_calls_th
               or executions    > l_executions_th
               or sharable_mem  > l_sharable_mem_th
               or version_count > l_version_count_th
              );

3)找出stats$v$sqlxs对象(spcusr.sql)

create or replace view STATS$V_$SQLXS as
select max(sql_text)        sql_text
     , sum(sharable_mem)    sharable_mem
     , sum(sorts)           sorts
     , min(module)          module
     , sum(loaded_versions) loaded_versions
     , sum(fetches)         fetches
     , sum(executions)      executions
     , sum(loads)           loads
     , sum(invalidations)   invalidations
     , sum(parse_calls)     parse_calls
     , sum(disk_reads)      disk_reads
     , sum(buffer_gets)     buffer_gets
     , sum(rows_processed)  rows_processed
     , max(command_type)    command_type
     , address              address
     , hash_value           hash_value
     , count(1)             version_count
     , sum(cpu_time)        cpu_time
     , sum(elapsed_time)    elapsed_time
     , max(outline_sid)     outline_sid
     , max(outline_category) outline_category
     , max(is_obsolete)     is_obsolete
     , max(child_latch)     child_latch
  from v$sql
 group by hash_value, address;
create or replace public synonym STATS$V$SQLXS for STATS$V_$SQLXS;

4)通过这里可以看出，要是的STATS$SQL_SUMMARY主键不重复，只要是的STATS$V_$SQLXS查询出来的记录唯一，所以解决方案就是在STATS$V_$SQLXS视图中增加下列条件，确保查询出来的记录唯一，从而不会发生主键冲突

where 
( plan_hash_value > 0 
or executions > 0
or parse_calls > 0
or disk_reads > 0
or buffer_gets > 0
)

该bug在10g中修复，对于不能及时升级的数据库，建议采用第五种方法解决问题，比较治标治本，对业务基本上无影响