------------------------------------------------------------------------------------ File name:   latchprofx.sql ( Latch Holder Profiler eXtended )-- Purpose:     Perform high-frequency sampling on V$LATCHHOLDER--              and present a profile of latches held by sessions--              including extended statistics about in which kernel--              function the latch held was taken---- Author:      Tanel Poder-- Copyright:   (c) http://www.tanelpoder.com--              -- Usage:       @latchprofx <what> <sid> <latch name> <#samples>--              @latchprofx name 350 % 100000                   - monitor all latches SID 350 is holding--              @latchprofx sid,name % library 1000000          - monitor which SIDs hold latches with "library" in their name--              @latchprofx sid,name,laddr % 40D993A0 100000    - monitor which SIDs hold child latch with address 0x40D993A0--              @latchprofx sid,name,func % % 100000--                                                              - monitor all sessions and latches and show--                                                              - latch get Where info (locations in kernel code--                                                              - where the latch get was done)----              @latchprofx sid,name,hmode,func 89 "cache buffers chains" 100000--                                                              - monitor functions that took latch for SID 89 only--                                                              - and report only "cache buffers chains" latch holders--                                                              - also report hold mode HMODE (shared or exclusive)----              @latchprofx sid,name,hmode,func,object % 40D993A0 100000--                                                              - monitor for what object's access the child latch at--                                                              - particular address was taken. for cache buffers chains--                                                              - latch the object means data block address (DBA)--                                                              - of the block accessed in buffer cache.--                                                              - you can translate the 6-byte DBA to rfile#/block#--                                                              - using dbms_utility or dba.sql script from TPT scripts---- Other:--              This script is based on X$ tables instead of V$ tables--              as some info required is not externalized to V$.--              So you need to run this script either as SYS or--              need to have relevant X$ proxy views created----              The sampling relies on NESTED LOOP join method and having--              X$KSUPRLAT as the inner (probed) table. ----              If sampling always reports a single latch event even though --              many different events (or parameter values) are expected then --              the execution plan used is not right.----              The join in exec plan step 9 MUST be a NESTED LOOPS join, this is how--              the high speed sampling is done.---- ------------------------------------------------------------------------------------------------------- | Id  | Operation                             | Name            | E-Rows |  OMem |  1Mem | Used-Mem |-- ------------------------------------------------------------------------------------------------------- |   1 |  MERGE JOIN CARTESIAN                 |                 |      1 |       |       |          |-- |   2 |   MERGE JOIN CARTESIAN                |                 |      1 |       |       |          |-- |*  3 |    FIXED TABLE FULL                   | X$KSUTM         |      1 |       |       |          |-- |   4 |    BUFFER SORT                        |                 |      1 |  9216 |  9216 | 8192  (0)|-- |   5 |     VIEW                              |                 |      1 |       |       |          |-- |   6 |      SORT ORDER BY                    |                 |      1 |  2048 |  2048 | 2048  (0)|-- |   7 |       HASH GROUP BY                   |                 |      1 |       |       |          |-- |   8 |        NESTED LOOPS OUTER             |                 |      1 |       |       |          |-- |   9 |         NESTED LOOPS                  |                 |      1 |       |       |          |-- |  10 |          VIEW                         |                 |      1 |       |       |          |-- |  11 |           CONNECT BY WITHOUT FILTERING|                 |        |       |       |          |-- |  12 |            FAST DUAL                  |                 |      1 |       |       |          |-- |* 13 |          FIXED TABLE FULL             | X$KSUPRLAT      |      1 |       |       |          |-- |* 14 |         FIXED TABLE FIXED INDEX       | X$KSLLW (ind:2) |      1 |       |       |          |-- |  15 |   BUFFER SORT                         |                 |      1 |  9216 |  9216 | 8192  (0)|-- |* 16 |    FIXED TABLE FULL                   | X$KSUTM         |      1 |       |       |          |-- ---------------------------------------------------------------------------------------------------------              If you want to drill down to latch child level, include "name" in first parameter to latchprof----              Then you can use la.sql (V$LATCH_PARENT/V$LATCH_CHILDREN) to--              map the latch address back to latch child#------------------------------------------------------------------------------------ what includes what columns to display & aggregate and also options like latch name filteringDEF _lhp_what="&1"DEF _lhp_sid="&2"DEF _lhp_name="&3"DEF _lhp_samples="&4"COL name FOR A35 TRUNCATECOL latchprof_total_ms HEAD "Held ms" FOR 999999.999COL latchprof_pct_total_samples head "Held %" format 999.99COL latchprof_avg_ms HEAD "Avg hold ms" FOR 999999.999COL dist_samples HEAD GetsCOL total_samples HEAD HeldCOL ksllwnam FOR A40 TRUNCATECOL ksllwlbl FOR A20 TRUNCATECOL objtype  FOR A20 TRUNCATECOL object   FOR A17 WRAP JUST RIGHTCOL hmode    FOR A12 TRUNCATECOL what     FOR A17 WRAPCOL func     FOR A40 TRUNCATEBREAK ON lhp_name SKIP 1DEF _IF_ORA_10_OR_HIGHER="--"PROMPTPROMPT -- LatchProfX 2.02 by Tanel Poder ( http://www.tanelpoder.com )COL latchprof_oraversion NEW_VALUE _IF_ORA_10_OR_HIGHERSET TERMOUT OFFSELECT     DECODE(SUBSTR(BANNER, INSTR(BANNER, 'Release ')+8,1), 1, '', '--') latchprof_oraversion FROM v$version WHERE ROWNUM=1;SET TERMOUT ONWITH     t1 AS (SELECT hsecs FROM v$timer),    samples AS (        SELECT /*+ ORDERED USE_NL(l.x$ksuprlat) USE_NL(s.x$ksuse) NO_TRANSFORM_DISTINCT_AGG */            &_lhp_what            &_IF_ORA_10_OR_HIGHER , COUNT(DISTINCT gets)        dist_samples          , COUNT(*)                    total_samples          , COUNT(*) / &_lhp_samples    total_samples_pct        FROM             (SELECT /*+ NO_MERGE */ 1 FROM DUAL CONNECT BY LEVEL <= &_lhp_samples) s,            (SELECT ksuprpid PID, ksuprsid SID, ksuprlnm NAME, ksuprlat LADDR, ksulawhr,                     TO_CHAR(ksulawhy,'XXXXXXXXXXXXXXXX') object                    &_IF_ORA_10_OR_HIGHER , ksulagts GETS                    &_IF_ORA_10_OR_HIGHER , lower(ksuprlmd) HMODE             FROM x$ksuprlat) l,            (SELECT                    indx                  , ksusesqh     sqlhash                  , ksusesql     sqladdr                   &_IF_ORA_10_OR_HIGHER , ksusesph planhash                  &_IF_ORA_10_OR_HIGHER , ksusesch sqlchild                  &_IF_ORA_10_OR_HIGHER , ksusesqi sqlid             FROM x$ksuse) s,            (SELECT indx,                     ksllwnam func, ksllwnam,                    ksllwlbl objtype, ksllwlbl              FROM x$ksllw) w        WHERE            l.sid LIKE '&_lhp_sid'        AND l.ksulawhr = w.indx (+)        AND l.sid = s.indx        AND (LOWER(l.name) LIKE LOWER('%&_lhp_name%') OR LOWER(RAWTOHEX(l.laddr)) LIKE LOWER('%&_lhp_name%'))        GROUP BY            &_lhp_what        ORDER BY            total_samples DESC    ),    t2 AS (SELECT hsecs FROM v$timer)SELECT /*+ ORDERED */    &_lhp_what  , s.total_samples  &_IF_ORA_10_OR_HIGHER , s.dist_samples--  , s.total_samples_pct  , s.total_samples / &_lhp_samples * 100 latchprof_pct_total_samples  , (t2.hsecs - t1.hsecs) * 10 * s.total_samples / &_lhp_samples latchprof_total_ms--  , s.dist_events    &_IF_ORA_10_OR_HIGHER , (t2.hsecs - t1.hsecs) * 10 * s.total_samples / dist_samples / &_lhp_samples latchprof_avg_ms  FROM    t1,    samples s,    t2  WHERE ROWNUM <= 20/COL name    CLEARCOL hmode   CLEARCOL what    CLEARCOL func    CLEARCOL objtype CLEAR

latchprof.sql

------------------------------------------------------------------------------------ File name:   latchprof.sql ( Latch Holder Profiler )-- Purpose:     Perform high-frequency sampling on V$LATCHHOLDER--              and present a profile of latches held by sessions---- Author:      Tanel Poder-- Copyright:   (c) http://www.tanelpoder.com--              -- Usage:       @latchprof <what> <sid> <latch name> <#samples>--              @latchprof name 350 % 100000                - monitor all latches SID 350 is holding--              @latchprof sid,name % library 1000000       - monitor which SIDs hold latches with "library" in their name--              @latchprof sid,name,laddr % 40D993A0 100000 - monitor which SIDs hold child latch with address 0x40D993A0-- Other:--              The sampling relies on NESTED LOOP join method and having--              V$LATCHHOLDER as the inner (probed) table. Note that on 9i--              you may need to run this script as SYS as it looks like otherwise--              the global USE_NL hint is not propagated down to X$ base tables----              The join in exec plan step 8 MUST be a NESTED LOOPS join, this is how--              the high speed sampling of changing dataset from V$LATCHHOLDER--              is done, otherwise you will not see correct results.---- ------------------------------------------------------------------------------------------------- | Id  | Operation                            | Name       | E-Rows |  OMem |  1Mem | Used-Mem |-- ------------------------------------------------------------------------------------------------- |   1 |  MERGE JOIN CARTESIAN                |            |      1 |       |       |          |-- |   2 |   MERGE JOIN CARTESIAN               |            |      1 |       |       |          |-- |*  3 |    FIXED TABLE FULL                  | X$KSUTM    |      1 |       |       |          |-- |   4 |    BUFFER SORT                       |            |      1 |  9216 |  9216 | 8192  (0)|-- |   5 |     VIEW                             |            |      1 |       |       |          |-- |   6 |      SORT ORDER BY                   |            |      1 |  2048 |  2048 | 2048  (0)|-- |   7 |       SORT GROUP BY                  |            |      1 |  9216 |  9216 | 8192  (0)|-- |   8 |        NESTED LOOPS                  |            |      1 |       |       |          |-- |   9 |         VIEW                         |            |      1 |       |       |          |-- |  10 |          CONNECT BY WITHOUT FILTERING|            |        |       |       |          |-- |  11 |           FAST DUAL                  |            |      1 |       |       |          |-- |* 12 |         FIXED TABLE FULL             | X$KSUPRLAT |      1 |       |       |          |-- |  13 |   BUFFER SORT                        |            |      1 |  9216 |  9216 | 8192  (0)|-- |* 14 |    FIXED TABLE FULL                  | X$KSUTM    |      1 |       |       |          |-- ---------------------------------------------------------------------------------------------------              If you want to drill down to latch child level, include "laddr" in first parameter--              to latchprof----              Then you can use la.sql (V$LATCH_PARENT/V$LATCH_CHILDREN) to--              map the latch address back to latch child# if needed------------------------------------------------------------------------------------ what includes what columns to display & aggregate and also options like latch name filteringDEF _lhp_what="&1"DEF _lhp_sid="&2"DEF _lhp_name="&3"DEF _lhp_samples="&4"COL name FOR A35 TRUNCATE COL latchprof_total_ms HEAD "Held ms" FOR 999999.999COL latchprof_pct_total_samples head "Held %" format 999.99COL latchprof_avg_ms HEAD "Avg hold ms" FOR 999.999COL dist_samples HEAD GetsCOL total_samples HEAD HeldBREAK ON lhp_name SKIP 1DEF _IF_ORA_10_OR_HIGHER="--"PROMPTPROMPT -- LatchProf 2.02 by Tanel Poder ( http://www.tanelpoder.com )COL latchprof_oraversion NEW_VALUE _IF_ORA_10_OR_HIGHERSET TERMOUT OFFSELECT DECODE(SUBSTR(BANNER, INSTR(BANNER, 'Release ')+8,1), 1, '', '--') latchprof_oraversion FROM v$version WHERE ROWNUM=1;SET TERMOUT ONWITH     t1 AS (SELECT hsecs FROM v$timer),    samples AS (        SELECT /*+ ORDERED USE_NL(l) USE_NL(s) USE_NL(l.gv$latchholder.x$ksuprlat) NO_TRANSFORM_DISTINCT_AGG  */            &_lhp_what          &_IF_ORA_10_OR_HIGHER , COUNT(DISTINCT gets)      dist_samples          , COUNT(*)                    total_samples          , COUNT(*) / &_lhp_samples    total_samples_pct        FROM             (SELECT /*+ NO_MERGE */ 1 FROM DUAL CONNECT BY LEVEL <= &_lhp_samples) s,            v$latchholder l,            (SELECT                    sid                                     indx                  , sql_hash_value                          sqlhash                  , sql_address                             sqladdr                   &_IF_ORA_10_OR_HIGHER , sql_child_number  sqlchild                  &_IF_ORA_10_OR_HIGHER , sql_id            sqlid             FROM v$session) s        WHERE            l.sid LIKE '&_lhp_sid'        AND (LOWER(l.name) LIKE LOWER('%&_lhp_name%') OR LOWER(RAWTOHEX(l.laddr)) LIKE LOWER('%&_lhp_name%'))        AND l.sid = s.indx        GROUP BY            &_lhp_what        ORDER BY            total_samples DESC    ),    t2 AS (SELECT hsecs FROM v$timer)SELECT /*+ ORDERED */    &_lhp_what  , s.total_samples  &_IF_ORA_10_OR_HIGHER , s.dist_samples  --  , s.total_samples_pct  , s.total_samples / &_lhp_samples * 100 latchprof_pct_total_samples  , (t2.hsecs - t1.hsecs) * 10 * s.total_samples / &_lhp_samples latchprof_total_ms  --   s.dist_events,  &_IF_ORA_10_OR_HIGHER , (t2.hsecs - t1.hsecs) * 10 * s.total_samples / dist_samples / &_lhp_samples latchprof_avg_ms  FROM    t1,    samples s,    t2  WHERE ROWNUM <= 30/COL name CLEAR