V $ SESSION SQL _ID is blank. SQL _ID and sessionsql_id cannot be found

V $ SESSION SQL _ID is blank. SQL _ID and sessionsql_id cannot be found

Brother, have you ever encountered the embarrassment of querying V $ SESSION. SQL _ID but SQL _ID is null and cannot be found? Too many people have asked this question.

I believe that you do not have any good solutions from Baidu/GOOGLE. Today I will share a method to teach you how to grasp SQL (this method is based on ORACLE11G, and you can wash your bed at 10G ).

First, let's make an experiment:

SQL> select sid from v $ mystat where rownum = 1;
 
SID
----------
1150
 
SQL> update test set owner = 'bigsb 'where object_id <100;
 
98 rows updated

Execute an UPDATE statement in the SESSION 1150. do not submit the UPDATE statement.

SQL> select sid from v $ mystat where rownum = 1;
 
SID
----------
1338
 
SQL> update test set owner = 'SB 'where object_id <10;

Run another UPDATE in 1338. Because 1150 is not submitted, 1138 is in the row lock wait state.

In this case, use the following script to query the database:

SQL> select inst_id,  2         sid,  3         sql_id,  4         event,  5         blocking_session,  6         blocking_instance  7    from gv$session a  8   where blocking_session is not null;    INST_ID        SID SQL_ID        EVENT                                   BLOCKING_SESSION BLOCKING_INSTANCE---------- ---------- ------------- --------------------------------------- ---------------- ----------------         1       1338 852mvmth18w37 enq: TX - row lock contention           1150                 1         SQL> select sql_id from gv$session where inst_id=1 and sid=1150; SQL_ID-------------

Indeed, SQL _ID is null. Some people may say, I will query PREV_ SQL _ID. Well, let's try it. The SQL _ID is the SQL _ID of the transaction, not the SQL _ID of UPDATE.

SQL>  select prev_sql_id from gv$session where inst_id=1 and sid=1150; PREV_SQL_ID-------------9m7787camwh4m SQL> select sql_text from gv$sql where sql_id='9m7787camwh4m'; SQL_TEXT--------------------------------------------------------------------------------begin :id := sys.dbms_transaction.local_transaction_id; end;

So a lot of people suffer from this time and don't know what to do. Another method is provided.

SQL> select PREV_EXEC_START,USERNAME,MODULE,ACTION FROM GV$SESSION WHERE INST_ID=1 AND SID=1150; PREV_EXEC_START     USERNAME    MODULE               ACTION---------------     ------------------------------ -----------------------2015-04-10 18:01:44 SCOTT       PL/SQL Developer    Command Window - NewSQL> SELECT SQL_ID,SQL_TEXT,LAST_ACTIVE_TIME,MODULE,ACTION FROM GV$SQL WHERE INST_ID=1 AND LAST_ACTIVE_TIME=TO_DATE('2015-04-10 18:01:44','YYYY-MM-DD HH24:MI:SS'); SQL_ID        SQL_TEXT                                                                         LAST_ACTIVE_TIME MODULE              ACTION------------- -------------------------------------------------------------------------------- ---------------- ---------------------------------------------------------------- ----------------------------------------------------------------2syvqzbxp4k9z select u.name, o.name, a.interface_version#, o.obj#      from association$ a, us 2015/4/10 18:01:                                                                  6c9wx6z8w9qpu select a.default_selectivity                             from association$ a     2015/4/10 18:01:                    2xyb5d6xg9srh select a.default_cpu_cost, a.default_io_cost             from association$ a     2015/4/10 18:01:                                                                  d1s917pgj7650  update test set owner='BIGSB' where object_id<100                               2015/4/10 18:01: PL/SQL Developer    Command Window - New 

Now you can capture the SQL

Note:

1. In the case of high concurrency, multiple suspicious SQL statements may occur.

2. LAST_ACTIVE_TIME and PREV_EXEC_START may have a small error (in seconds)

In this case, please make your own judgment and never be too stupid.

select a.inst_id, a.sid, a.sql_id, b.sql_id, b.sql_text  from gv$session a, gv$sql b where a.inst_id = b.inst_id   and a.PREV_EXEC_START = b.LAST_ACTIVE_TIME   and a.USERNAME = b.PARSING_SCHEMA_NAME   and a.MODULE_HASH = b.MODULE_HASH   and a.ACTION_HASH = b.ACTION_HASH      select a.inst_id,       a.sid,       a.event,       a.sql_id,       b.sql_text          running_sql,       c.sql_in_session,       c.sql_id_in_v$sql,       c.sql_text          blocking_sql,       a.blocking_session,       a.blocking_instance  from gv$session a,       (select sql_id, sql_text          from (select sql_id,                       sql_text,                       row_number() over(partition by sql_id order by sql_id) as rn                  from gv$sql)         where rn = 1) b,       (select a.inst_id,               a.sid,               a.sql_id   sql_in_session,               b.sql_id   sql_id_in_v$sql,               b.sql_text          from gv$session a, gv$sql b         where a.inst_id = b.inst_id           and a.PREV_EXEC_START =b.LAST_ACTIVE_TIME           and a.USERNAME = b.PARSING_SCHEMA_NAME           and a.MODULE_HASH = b.MODULE_HASH           and a.ACTION_HASH = b.ACTION_HASH) c where a.sql_id = b.sql_id   and a.blocking_session is not null   and a.BLOCKING_SESSION = c.sid   and a.BLOCKING_INSTANCE = c.inst_id;