RAC 环境Library Cache Lock的处理方法

RAC 环境Library Cache Lock的处理方法

我要监控某个Job,该session 处于 Library cache lock 等待中

数据库有2个节点
SQL> select inst_id from gv$instance;

   INST_ID
----------
         2
         1

SQL> select inst_id,sid,serial#,event ,p1raw,machine,status from gv$session where username='BX5685';

   INST_ID        SID    SERIAL# EVENT                          P1RAW            MACHINE              STATUS
---------- ---------- ---------- ------------------------------ ---------------- -------------------- ---------------
         1       4538      39833 library cache lock             C000000346FBA458 bdhp4462             ACTIVE
    
在Node1上面查询   
SQL> select * from dba_kgllock where kgllkreq > 0;

KGLLKUSE         KGLLKHDL           KGLLKMOD   KGLLKREQ KGLLKTYPE
---------------- ---------------- ---------- ---------- ------------
C0000004789EF9D0 C000000346FBA458          0          2 Lock

SQL> select kglnaown, kglnaobj from x$kglob where kglhdadr = 'C000000346FBA458';

KGLNAOWN             KGLNAOBJ
-------------------- --------------------
IDWSU1               PROD_ASSOC_DNORM

SQL> select kglhdadr, kglnaown, kglnaobj from x$kglob where kglnaobj = 'PROD_ASSOC_DNORM' and KGLNAOWN='IDWSU1';

KGLHDADR         KGLNAOWN             KGLNAOBJ
---------------- -------------------- --------------------
C000000346FBA458 IDWSU1               PROD_ASSOC_DNORM

在Node2上面查询
SQL> select kglhdadr, kglnaown, kglnaobj from x$kglob where kglnaobj = 'PROD_ASSOC_DNORM' and KGLNAOWN='IDWSU1';

KGLHDADR                       KGLNAOWN             KGLNAOBJ
------------------------------ -------------------- ------------------------------
C000000443267070               IDWSU1               PROD_ASSOC_DNORM
C00000035C33E248               IDWSU1               PROD_ASSOC_DNORM

SQL> col event format a30
select sid, serial#,s.event, sql_text from dba_kgllock w, v$session s, v$sqlarea a
where w.kgllkuse = s.saddr and w.kgllkhdl='C000000443267070'
and s.sql_address = a.address
and s.sql_hash_value = a.hash_value;SQL>   2    3    4

       SID    SERIAL# EVENT                          SQL_TEXT
---------- ---------- ------------------------------ --------------------------------------------------
      4774      36583 db file scattered read         ALTER TABLE PROD_ASSOC_DNORM ENABLE CONSTRAINT PRO
                                                     D_ASSOC_DNORM_PK USING INDEX STORAGE ( INITIAL 419
                                                     4304 NEXT 4194304 PCTINCREASE 0 ) TABLESPACE CDW_R
                                                     EFERENCE01M LOCAL
很明显了，节点1的session 在等待节点2 的session 进行alter table操作

那么节点1的 Job 也只能等待节点2的session完成了才能继续工作。