el holgazán

Esta query nos ha salvado ya de bastantes apuros, con que se merece un artículo para ella sola.

Se utiliza para detectar casos en los que una sesión de usuario de Oracle está bloqueando a otra, haciendo que este último permanezca a la espera. Proporciona bastante información tanto del usuario bloqueante como del que está a la espera.

Ahí va:

SELECT  BS.USERNAME       "Blocking User",
       BS.USERNAME       "DB User",
       WS.USERNAME       "Waiting User",
       BS.SID            "SID",
       WS.SID            "WSID",
       BS.SERIAL#        "Serial#",
       BS.SQL_ADDRESS    "address",
       BS.SQL_HASH_VALUE "Sql hash",
       BS.PROGRAM        "Blocking App",
       WS.PROGRAM        "Waiting App",
       BS.MACHINE        "Blocking Machine",
       WS.MACHINE        "Waiting Machine",
       BS.OSUSER         "Blocking OS User",
       WS.OSUSER         "Waiting OS User",
       BS.SERIAL#        "Serial#",
       WS.SERIAL#        "WSerial#",
       DECODE(WK.TYPE,'MR','Media Recovery',
                      'RT','Redo Thread',
                      'UN','USER Name',
                      'TX','Transaction',
                      'TM','DML',
                      'UL','PL/SQL USER LOCK',
                      'DX','Distributed Xaction',
                      'CF','Control FILE',
                      'IS','Instance State',
                      'FS','FILE SET',
                      'IR','Instance Recovery',
                      'ST','Disk SPACE Transaction',
                      'TS','Temp Segment',
                      'IV','Library Cache Invalidation',
                      'LS','LOG START OR Switch',
                      'RW','ROW Wait',
                      'SQ','Sequence Number',
                      'TE','Extend TABLE',
                      'TT','Temp TABLE',
                      WK.TYPE) LOCK_TYPE,
       DECODE(HK.LMODE,0,'None',
                       1,'NULL',
                       2,'ROW-S (SS)',
                       3,'ROW-X (SX)',
                       4,'SHARE',
                       5,'S/ROW-X (SSX)',
                       6,'EXCLUSIVE',
                       TO_CHAR(HK.LMODE)) MODE_HELD,
       DECODE(WK.REQUEST,0,'None',
                         1,'NULL',
                         2,'ROW-S (SS)',
                         3,'ROW-X (SX)',
                         4,'SHARE',
                         5,'S/ROW-X (SSX)',
                         6,'EXCLUSIVE',
                         TO_CHAR(WK.REQUEST)) MODE_REQUESTED,
       TO_CHAR(HK.ID1)   LOCK_ID1,
       TO_CHAR(HK.ID2)   LOCK_ID2,
       DECODE(HK.BLOCK,0,'NOT Blocking', /* Not blocking any other processes */
                       1,'Blocking', /* This lock blocks other processes */
                       2,'Global', /* This lock is global, so we can't tell */
                       TO_CHAR(HK.BLOCK)) BLOCKING_OTHERS
FROM     V$LOCK HK,
       V$SESSION BS,
       V$LOCK WK,
       V$SESSION WS
WHERE    HK.BLOCK = 1
       AND HK.LMODE != 0
       AND HK.LMODE != 1
       AND WK.REQUEST != 0
       AND WK.TYPE (+)  = HK.TYPE
       AND WK.ID1 (+)  = HK.ID1
       AND WK.ID2 (+)  = HK.ID2
       AND HK.SID = BS.SID (+)
       AND WK.SID = WS.SID (+)
       AND (BS.USERNAME IS NOT NULL)
       AND (BS.USERNAME <> 'SYSTEM')
       AND (BS.USERNAME <> 'SYS')
ORDER BY 1;