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Archive for January, 2022

Part 3: Using SQLT (SQLTXPLAIN) tool with Data Guard physical standby databases

Posted by FatDBA on January 28, 2022

SQLT (Oracle’s Tool written by Carlos Sierra, read MOS note 215187.1 for more details) is an important tool when it comes to doing in-depth and advance troubleshooting & analysis of a SQL statement, it’s pretty easy to install, configure and use, but things gets little tricky when it comes to running it for the SQL that is slow or in question on the read-only standby database. The problem is obvious as ADG or standby databases doesn’t allow WRITE operations and you will get error “ORA-16000: database open for read-only access” when try on standby database

The only problem being that SQLTXTRACT and SQLTXECUTE need read/write access to the database (to store data in the SQLT repository and to install packages and procedures). How is it possible for SQLT to help us if we can’t even store data about the performance on the database with the performance problem? This is where SQLTXTRSBY comes into play. XTRSBY solves this problem by using local users (on a read/write database) and creating procedures that use database links to the read-only database.

First step : Install SQLTXPLAIN on the primary and allow the DDL to be propagated to the standby database.

-- On primary database
-- DDL Will get propogated to the standby in few secons/mins.	
[oracle@monkeyos1931jd install]$ sqlplus / as sysdba

SQL*Plus: Release 12.2.0.1.0 Production on Thu Jan 13 16:13:41 2022

Copyright (c) 1982, 2016, Oracle.  All rights reserved.


Connected to:
Oracle Database 12c Enterprise Edition Release 12.2.0.1.0 - 64bit Production

SQL>
SQL>
SQL> @1

   DB_UNIQUE_NAME     OPEN_MODE    DATABASE_ROLE
_________________ _____________ ________________
DIXITP            READ WRITE    PRIMARY

SQL>


SQL> START sqcreate.sql
        zip warning: name not matched: *_sq*.log
zip error: Nothing to do! (SQLT_installation_logs_archive.zip)
        zip warning: name not matched: *_ta*.log
........
...........
..............

SQUTLTEST completed.
  adding: 220113161601_10_squtltest.log (deflated 59%)

SQLT users must be granted SQLT_USER_ROLE before using this tool.

SQCREATE completed. Installation completed successfully.
SQL>
SQL>

Step 2 : Create a database link accessible to the SQLTXPLAIN schema linking to the standby database as changes will be fetched from the standby database SQLTXPLA in schema.

-- On Primary database to connect to the standby database.
SQL> create public database link dblink_tostandby connect to sqltxplain identified by oracle90 using 'DIXITSTAN';

Database link DBLINK_TOSTANDBY created.

SQL>
SQL>

SQL> select * from dba_db_links;

    OWNER                      DB_LINK      USERNAME        HOST      CREATED    HIDDEN
_________ ____________________________ _____________ ___________ ____________ _________
PUBLIC    DBLINK_TOSTANDBY             SQLTXPLAIN    DIXITSTAN    16-JAN-22    NO



SQL> select sysdate from dual@DBLINK_TOSTANDBY;

     SYSDATE
____________
16-JAN-22

SQL>

Step 3: Let’s run some SQLs on standby database which we will using against the SQLT tool as an input to generate the SQLT report.

-- On Standby Database
SQL> @1

DB_UNIQUE_NAME                 OPEN_MODE            DATABASE_ROLE
------------------------------ -------------------- ----------------
DIXITSTAN                       READ ONLY WITH APPLY PHYSICAL STANDBY

SQL>
SQL> select count(*) from bigtab where weight in ( select distinct( weight) from bigtab);

  COUNT(*)
----------
   2431464

SQL> select sql_id, sql_fulltext from v$sqlarea where sql_text like '%distinct( weight) from bigtab%';

SQL_ID        SQL_FULLTEXT
------------- --------------------------------------------------------------------------------------------------------------------------------------------
6mg40znnrhzm8 select count(*) from bigtab where weight in ( select distinct( weight) from bigtab)

In the steps above we ran some arbitrary SQL and got the SQL ID for that SQL. Remember we ran the SQL on the standby database (where our reports might have run). We can’t store any data on the Data Guard Physical Standby database so now we have to capture information about the SQL from across the database link from the primary database.

Step 4: Will run the SQLT for SQLID that we have captured from STANDBY database, from PRIMARY database. The script “sqltxtrsby.sql” is present under RUN directory of the tool.

[oracle@monkeyos1931jd run]$ ls *sqltxtrsby*
sqltxtrsby.sql


[oracle@monkeyos1931jd run]$ !sql
sqlplus

SQL*Plus: Release 12.2.0.1.0 Production on Sun Jan 16 06:01:12 2022

Copyright (c) 1982, 2016, Oracle.  All rights reserved.

Enter user-name: / as sysdba

Connected to:
Oracle Database 12c Enterprise Edition Release 12.2.0.1.0 - 64bit Production

SQL> 
SQL> @1

   DB_UNIQUE_NAME     OPEN_MODE    DATABASE_ROLE
_________________ _____________ ________________
DIXITP            READ WRITE    PRIMARY


SQL> 
SQL> @sqltxtrsby 6mg40znnrhzm8 DBLINK_TOSTANDBY

PL/SQL procedure successfully completed.

Parameter 1:
SQL_ID or HASH_VALUE of the SQL to be extracted (required)

Paremeter 2:
SQLTXPLAIN password (required)

PL/SQL procedure successfully completed.
PL/SQL procedure successfully completed.

Parameter 3:
DBLINK to stand-by database (required)

Enter value for 3: DBLINK_TOSTANDBY

Values passed to sqltxtrsby:
SQL_ID_OR_HASH_VALUE: "6mg40znnrhzm8"
DB_LINK             : "@DBLINK_TOSTANDBY"


PL/SQL procedure successfully completed.


SQLT_VERSION
----------------------------------------
SQLT version number: 19.1.200226
SQLT version date  : 2020-02-26
Installation date  : 2022-01-13/16:15:27

... please wait ...
  adding: alert_DIXITP.log (deflated 86%)

NOTE:
You used the XTRSBY method connected as SYS.

.......
..............
...............
....
..................
File sqlt_s19812_xtrsby_6mg40znnrhzm8.zip for 6mg40znnrhzm8 has been created.

SQLTXTRSBY completed.

Now look out for sqlt_xxxx_main.html file, We’ll see the main sqlt_xxxx_main.html file, but fewer files than for a “normal” sqltxtract run: no 10053 trace file, no SQL profile script and no SQL Tuning Advisor reports. This is because the read-only status of the standby restricts what can be done.

Hope It Helped!
Prashant Dixit

Posted in Advanced, troubleshooting | Tagged: , , , , | Leave a Comment »

Part 2 : Creating custom SQL Profile for a slow SQL in a Data Guard physical standby database

Posted by FatDBA on January 19, 2022

Someone asked me lately if its possible to fix a plan for a bad/slow SELECT SQL in a Data Guard environment ? The guy was asking as he was using ‘coe_xfr_sql_profile.sql‘, the script that you can use to create custom SQL Profiles to correct optimizer cost estimates to encourage good execution plans for a SQL.

Well, the post is not about using it to fix SQL plans, but is to understand how to fix a plan for a SQL that is slow on standby environment. Because if you go and try to execute the script that SQLT generates you will get ‘ORA-00600: internal error’ as dataguard is always opened in the RO mode and you cannot write anything on the database, so the question is – How to fix the plan then for a standby database ?

Here in the example, I’ve got a ADG setup with name ‘TESTSTANDBY’ and one of the SELECT statement with SQL ID 0y521mggg73pk that is slow and it has 4 different plan hash values (PHV) and there is plan flip that happens and due to that sometimes it picks the wrong plan and that’s when it goes slow. Here 1469174702 is the PHV that is WORST and both 3847062775 and 2797333706 PHVs are BEST and we can any of the two.

SQL> @1

DB_UNIQUE_NAME                 OPEN_MODE            DATABASE_ROLE
------------------------------ -------------------- ----------------
TESTSTANDBY                    READ ONLY WITH APPLY PHYSICAL STANDBY



SQL_ID        SUM(EXECS)   MIN_ETIME   MAX_ETIME   NORM_STDDEV
------------- ---------- ----------- ----------- -------------
0y521mggg73pk         32         .03        9.34      143.6554


SQL> @2
Enter value for sql_id: 0y521mggg73pk

SQL_ID        PLAN_HASH_VALUE        EXECS    AVG_ETIME AVG_CPU_TIME        AVG_LIO      AVG_PIO
------------- --------------- ------------ ------------ ------------ -------------- ------------
0y521mggg73pk      3847062775           10         .032         .021        1,448.0           .0
0y521mggg73pk      2797333706           10         .032         .021        1,448.0           .0
0y521mggg73pk      1687052623           10         .034         .025        1,448.0           .0
0y521mggg73pk      1469174702            2        9.340        1.021      541,054.0      4,155.5



-- This is what you will receive if try to run it on STANDBY database. 
SQL> @coe_xfr_sql_profile_0y521mggg73pk_3847062775.sql

DECLARE
*
ERROR at line 1:
ORA-00600: internal error code, arguments: [2652], [108], [108], [0], [0], [3891200], [], [], [], [], [], []
ORA-06512: at "SYS.DBMS_SQLTUNE_INTERNAL", line 18876
ORA-06512: at "SYS.DBMS_SQLTUNE", line 9368
ORA-06512: at "SYS.DBMS_SQLTUNE", line 9328
ORA-06512: at line 37

So, what you have to do here, you need to move the file (do scp, ftp, cp whatever) ‘coe_xfr_sql_profile_0y521mggg73pk_3847062775.sql‘ that is produced by the COE file, to the PRIMARY database and run that file from there and not on the standby.

-- Run the script on PRIMARY database
SQL>
SQL> @coe_xfr_sql_profile_0y521mggg73pk_3847062775.sql
SQL> REM
SQL> REM $Header: 215187.1 coe_xfr_sql_profile_0y521mggg73pk_3847062775.sql 11.4.4.4 2022/01/13 carlos.sierra $
SQL> REM
SQL> REM Copyright (c) 2000-2012, Oracle Corporation. All rights reserved.
SQL> REM
SQL> REM AUTHOR
SQL> REM   carlos.sierra@oracle.com
SQL> REM
SQL> REM SCRIPT
SQL> REM   coe_xfr_sql_profile_0y521mggg73pk_3847062775.sql
SQL> REM
SQL> REM DESCRIPTION
SQL> REM   This script is generated by coe_xfr_sql_profile.sql
SQL> REM   It contains the SQL*Plus commands to create a custom
SQL> REM   SQL Profile for SQL_ID 0y521mggg73pk based on plan hash
SQL> REM   value 3847062775.
SQL> REM   The custom SQL Profile to be created by this script
SQL> REM   will affect plans for SQL commands with signature
SQL> REM   matching the one for SQL Text below.
SQL> REM   Review SQL Text and adjust accordingly.
SQL> REM
SQL> REM PARAMETERS
SQL> REM   None.
SQL> REM
SQL> REM EXAMPLE
SQL> REM   SQL> START coe_xfr_sql_profile_0y521mggg73pk_3847062775.sql;
SQL> REM
SQL> REM NOTES
SQL> REM   1. Should be run as SYSTEM or SYSDBA.
SQL> REM   2. User must have CREATE ANY SQL PROFILE privilege.
SQL> REM   3. SOURCE and TARGET systems can be the same or similar.
SQL> REM   4. To drop this custom SQL Profile after it has been created:
SQL> REM         EXEC DBMS_SQLTUNE.DROP_SQL_PROFILE('coe_0y521mggg73pk_3847062775');
SQL> REM   5. Be aware that using DBMS_SQLTUNE requires a license
SQL> REM         for the Oracle Tuning Pack.
SQL> REM   6. If you modified a SQL putting Hints in order to produce a desired
SQL> REM         Plan, you can remove the artifical Hints from SQL Text pieces below.
SQL> REM         By doing so you can create a custom SQL Profile for the original
SQL> REM         SQL but with the Plan captured from the modified SQL (with Hints).
SQL> REM
SQL> WHENEVER SQLERROR EXIT SQL.SQLCODE;
SQL> REM
SQL> VAR signature NUMBER;
SQL> VAR signaturef NUMBER;
SQL> REM
SQL> DECLARE
  2  sql_txt CLOB;
  3  h       SYS.SQLPROF_ATTR;
  4  PROCEDURE wa (p_line IN VARCHAR2) IS
  5  BEGIN
  6  DBMS_LOB.WRITEAPPEND(sql_txt, LENGTH(p_line), p_line);
  7  END wa;
  8  BEGIN
  9  DBMS_LOB.CREATETEMPORARY(sql_txt, TRUE);
 10  DBMS_LOB.OPEN(sql_txt, DBMS_LOB.LOB_READWRITE);
 11  -- SQL Text pieces below do not have to be of same length.
 12  -- So if you edit SQL Text (i.e. removing temporary Hints),
 13  -- there is no need to edit or re-align unmodified pieces.
 14  wa(q'[/* SQL Analyze(63,1) */ DELETE FROM PRTINSTANCEITER PII WHERE EX]');
 15  wa(q'[ISTS ( SELECT 1 FROM PRTPROCESS PP WHERE PP.INSTANCEID = PII.INS]');
 16  wa(q'[TANCEID||':'||PII.LASTITERATION AND CURRENTTIME < :B1 AND (STATU]');
 17  wa(q'[S = 4 OR STATUS = 5)) AND ROWNUM <=10000]');
 18  DBMS_LOB.CLOSE(sql_txt);
 19  h := SYS.SQLPROF_ATTR(
 20  q'[BEGIN_OUTLINE_DATA]',
 21  q'[IGNORE_OPTIM_EMBEDDED_HINTS]',
 22  q'[OPTIMIZER_FEATURES_ENABLE('12.2.0.1')]',
 23  q'[DB_VERSION('12.2.0.1')]',
 24  q'[ALL_ROWS]',
 25  q'[OUTLINE_LEAF(@"SEL$3BA1AD7C")]',
 26  q'[UNNEST(@"SEL$1")]',
 27  q'[OUTLINE(@"DEL$1")]',
 28  q'[OUTLINE(@"SEL$1")]',
 29  q'[INDEX_RS_ASC(@"SEL$3BA1AD7C" "PP"@"SEL$1" ("PRTPROCESS"."CURRENTTIME" "PRTPROCESS"."STATUS"))]',
 30  q'[BATCH_TABLE_ACCESS_BY_ROWID(@"SEL$3BA1AD7C" "PP"@"SEL$1")]',
 31  q'[FULL(@"SEL$3BA1AD7C" "PII"@"DEL$1")]',
 32  q'[LEADING(@"SEL$3BA1AD7C" "PP"@"SEL$1" "PII"@"DEL$1")]',
 33  q'[USE_HASH(@"SEL$3BA1AD7C" "PII"@"DEL$1")]',
 34  q'[END_OUTLINE_DATA]');
 35  :signature := DBMS_SQLTUNE.SQLTEXT_TO_SIGNATURE(sql_txt);
 36  :signaturef := DBMS_SQLTUNE.SQLTEXT_TO_SIGNATURE(sql_txt, TRUE);
 37  DBMS_SQLTUNE.IMPORT_SQL_PROFILE (
 38  sql_text    => sql_txt,
 39  profile     => h,
 40  name        => 'coe_0y521mggg73pk_3847062775',
 41  description => 'coe 0y521mggg73pk 3847062775 '||:signature||' '||:signaturef||'',
 42  category    => 'DEFAULT',
 43  validate    => TRUE,
 44  replace     => TRUE,
 45  force_match => FALSE /* TRUE:FORCE (match even when different literals in SQL). FALSE:EXACT (similar to CURSOR_SHARING) */ );
 46  DBMS_LOB.FREETEMPORARY(sql_txt);
 47  END;
 48  /

PL/SQL procedure successfully completed.

SQL> WHENEVER SQLERROR CONTINUE
SQL> SET ECHO OFF;

            SIGNATURE
---------------------
  3905242471056150906


           SIGNATUREF
---------------------
  3905242471056150906


... manual custom SQL Profile has been created

not spooling currently

COE_XFR_SQL_PROFILE_0y521mggg73pk_3847062775 completed
SQL>
SQL>

Perfect, it ran successfully on the PRIMARY database, and the same will be transferred on to the STANDBY database by its own. Let’s check if its created or moved to the STANDBY database or not. Let’s query dba_sql_profiles to see if its there …

-- Lets check it on Standby
SQL> select NAME, SQL_TEXT, CREATED, STATUS from dba_sql_profiles order by created;

NAME                           SQL_TEXT                                                                         CREATED                        STATUS
------------------------------ -------------------------------------------------------------------------------- ------------------------------ --------
coe_0y521mggg73pk_3847062775   DELETE FROM BIGTABDIXITTAB PII WHERE EXISTS ( SELECT 1                          13-JAN-22 06.28.03.000000 AM   ENABLED

So, the issue is fixed on the standby and the SQL immediately picked the right plan that we asked it to follow.

Hope It Helped!
Prashant Dixit

Posted in Advanced, troubleshooting | Tagged: , , , | Leave a Comment »

Part 1 : Running SQL Tuning Advisor for a slow SQL in a Read Only Standby Database

Posted by FatDBA on January 15, 2022

Here goes my maiden post blog post from series about “Troubleshooting SQLs & other Issues on a Read Only Standby/Dataguard Environments” …

Recently I helped one of my customer stabilize performance of one of their critical DWH/BI decision support system workload running on an ADG (Physical Standby). At one time I have to generate SQL tuning advisory reports for few slow SQLs on the database, but that being a RO dataguard, it always ends with an error "ORA-13792: This operation requires a database link." when I try to call the SQL tuning advisor directly on the standby database.

So, this post is about how to run SQL Tuning advisor on a dataguard environment. Let’s assume we want to get SQLTA recommendation for this below SQL that is going for a FULL TABLE SCAN and is a costly SQL.

SQL> explain plan for select count(*) from bigtab where weight in ( select distinct( weight) from bigtab);

Explained.

SQL> select * from  table(dbms_xplan.display_cursor(null,null,'ALLSTATS LAST'));

PLAN_TABLE_OUTPUT
-------------------------------------------------------------------------------------------------
SQL_ID  0mauvkjsvmcmj, child number 1


Plan hash value: 2140185107

-----------------------------------------------------------------------------
| Id  | Operation          | Name   | Rows  | Bytes | Cost (%CPU)| Time     |
-----------------------------------------------------------------------------
|   0 | SELECT STATEMENT   |        |     1 |    13 |    74   (0)| 00:00:01 |
|   1 |  SORT AGGREGATE    |        |     1 |    13 |            |          |
|*  2 |   TABLE ACCESS FULL| BIGTAB | 80223 |  1018K|    74   (0)| 00:00:01 |
-----------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

   2 - filter("WEIGHT" IS NOT NULL)

This is what I have received on the standby database when tried to run the SQL Tuning advisor directly on it where it says that it requires a database link in order to run the advisory.

-- On standby database:
SQL>
SQL> @?/rdbms/admin/sqltrpt.sql


Specify the Sql id
~~~~~~~~~~~~~~~~~~
Enter value for sqlid: 0y521mggg73pk

Sql Id specified: 0y521mggg73pk

Tune the sql
~~~~~~~~~~~~
DECLARE
*
ERROR at line 1:
ORA-13792: This operation requires a database link.
ORA-06512: at line 36
ORA-06512: at "SYS.DBMS_SQLTUNE_UTIL1", line 1571
ORA-06512: at "SYS.DBMS_SYS_ERROR", line 79
ORA-06512: at "SYS.DBMS_SQLTUNE_UTIL1", line 1563
ORA-06512: at "SYS.DBMS_SQLTUNE", line 798
ORA-06512: at line 20


ERROR:
ORA-13608: The specified name NULL is invalid.
ORA-06512: at "SYS.DBMS_SQLTUNE_UTIL1", line 1571
ORA-06512: at "SYS.PRVT_ADVISOR", line 7080
ORA-06512: at "SYS.DBMS_SYS_ERROR", line 86
ORA-06512: at "SYS.PRVT_ADVISOR", line 85
ORA-06512: at "SYS.PRVT_ADVISOR", line 5938
ORA-06512: at "SYS.PRVT_ADVISOR", line 7011
ORA-06512: at "SYS.DBMS_SQLTUNE_UTIL1", line 1535
ORA-06512: at "SYS.DBMS_SQLTUNE", line 1324
ORA-06512: at line 1

In remote tuning, the database on which you initiate a tuning task differs from the database in which the tuning process executes or in which results are stored. For example, a standby database can have its own workload of queries, some of which may require tuning. You can issue SQL Tuning Advisor statements on a standby database. A standby-to-primary database link enables DBMS_SQLTUNE to write data to and read data from the primary database. The link is necessary because the standby database, which is read-only, cannot write the SQL tuning data.

Okay, for that first you need to create the DB Link between primary and the standby database, and same will be used by the SQL tuning advisor where it will do the write operations on the primary database. We will check its connectivity from the standby database if its working or not …

-- On Primary database
SQL> select username,common,account_status from dba_users where username ='SYS$UMF';

USERNAME        COM ACCOUNT_STATUS
--------------- --- --------------------------------
SYS$UMF         YES OPEN

-- On Primary database:
SQL> create database link lnk_to_pri connect to "SYS$UMF" identified by "oracle90" using 'DXTPRI';

Database link created.


-- On Standby database:
SQL> select  db_unique_name from v$database@lnk_to_pri;

DB_UNIQUE_NAME
------------------------------
DXTPRI

1 row selected.

SQL>


To tune a standby workload on a primary database, specify the database_link_to parameter in DBMS_SQLTUNE procedures. By default, the database_link_to parameter is null, which means that tuning is local. The database_link_to parameter must specify a private database link. This link must be owned by SYS and accessed by the default privileged user SYS$UMF. You issue all statements on the standby database. DBMS_SQLTUNE uses the database link both to fetch data from the primary database, and store data in the primary database.
Let’s create the TUNING TASK for the SQL Text.

-- run it on the STANDBY Database.
SQL>
SQL> 
DECLARE
my_task_name VARCHAR2(30);
my_sqltext CLOB;
BEGIN
my_sqltext := 'select count(*) from bigtab where weight in ( select distinct( weight) from bigtab)';
my_task_name := DBMS_SQLTUNE.CREATE_TUNING_TASK(
sql_text => my_sqltext,
task_name => 'TEST_sql_tuning_task1',
database_link_to => 'lnk_to_pri');
END;
/  
PL/SQL procedure successfully completed.

SQL>

-- Lets check if the tuning task is created 
SQL> SELECT task_name, STATUS, EXECUTION_start, EXECUTION_end FROM dba_advisor_log;

TASK_NAME
--------------------------------------------------------------------------------
STATUS      EXECUTION EXECUTION
----------- --------- ---------
TEST_sql_tuning_task1
EXECUTING   13-JAN-22

Next you need to execute the tuning task using the task_name you have assigned in the last step while creating the tuning task.

-- On Standby database
SQL> EXEC DBMS_SQLTUNE.execute_tuning_task(task_name => '&&your_sta_taks_name', database_link_to => 'lnk_to_pri');
Enter value for your_sta_taks_name: TEST_sql_tuning_task1

PL/SQL procedure successfully completed.

SQL>

Next, lets do the final step, generate the tuning task report with all recommendations for the SQL that is slow in the standby database.

-- Run it on the Standby database.
SQL>
SQL> SET LINES 150
SQL> SET pages 50000
SQL> SET long 5000000
SQL> SET longc 5000000
SQL> select dbms_sqltune.report_tuning_task('&&your_sta_taks_name', database_link_to => 'lnk_to_pri') from dual;
old   1: select dbms_sqltune.report_tuning_task('&&your_sta_taks_name', database_link_to => 'lnk_to_pri') from dual
new   1: select dbms_sqltune.report_tuning_task('TEST_sql_tuning_task1', database_link_to => 'lnk_to_pri') from dual

DBMS_SQLTUNE.REPORT_TUNING_TASK('TEST_SQL_TUNING_TASK1',DATABASE_LINK_TO=>'LNK_TO_PRI')
--------------------------------------------------------------------------------
GENERAL INFORMATION SECTION
----------------------------------------------------


RECOMMENDATIONS
------------------------------------------------------------------------------------------------------------------------------------------------------
GENERAL INFORMATION SECTION
-------------------------------------------------------------------------------
Tuning Task Name   : sql_tuning_task_5mxdwvuf9j3vp
Tuning Task Owner  : SYS
Workload Type      : Single SQL Statement
Scope              : COMPREHENSIVE
Time Limit(seconds): 60
Completion Status  : COMPLETED
Started at         : 01/13/2021 22:05:52
Completed at       : 01/13/2021 22:06:25

-------------------------------------------------------------------------------
Schema Name: SYS
SQL ID     : pdxdwvuf9j3co
SQL Text   : select count(*) from bigtab where weight in ( select distinct( weight) from bigtab)

-------------------------------------------------------------------------------
FINDINGS SECTION (1 finding)
-------------------------------------------------------------------------------

1- SQL Profile Finding (see explain plans section below)
--------------------------------------------------------
  A potentially better execution plan was found for this statement.

  Recommendation (estimated benefit: 99.94%)
  ------------------------------------------
  - Consider accepting the recommended SQL profile.
    execute dbms_sqltune.accept_sql_profile(task_name =>
            'sql_tuning_task_pdxdwvuf9j3co', task_owner => 'SYS', replace =>
            TRUE);

  Validation results
  ------------------

So, that’t it, you finally have the tuning recommendations for the slow SQL in the STANDBY database.

Hope It Helped!
Prashant Dixit

Posted in Advanced, troubleshooting | Tagged: , , , , | 3 Comments »

What are those strange columns in my execution plan OMem 1Mem O/1/M and Used-Mem ?

Posted by FatDBA on January 12, 2022

Few of the readers after my last post asked me – What are those strange columns named ‘OMem’, ‘1Mem’ and ‘O/1/M’ or ‘Used-Mem’ in execution plan ? This is something what you will see in the execution plan if called the DBMS_XPLAN using ‘+memstats’ or the ‘+allstats’ options.

----------------------------           -----------------------------
|  OMem |  1Mem |  O/1/M   |   OR      |  OMem |  1Mem | Used-Mem   |
----------------------------           -----------------------------
--
--
SQL> SELECT * FROM table(DBMS_XPLAN.DISPLAY_CURSOR('0m329sngnhv1p', 0, 'ALLSTATS'));

PLAN_TABLE_OUTPUT
-----------------------------------------------------------------------------------------
SQL_ID  0m329sngnhv1p, child number 0
-------------------------------------
SELECT /*+ gather_plan_statistics */ * FROM (xxxxxxxxxxxxxx

Plan hash value: xxxxxx

----------------------------------------------------------------------------------------------------------------------------------------
| Id  | Operation                                  | Name     | Starts | E-Rows | A-Rows |   A-Time   | Buffers |  OMem |  1Mem | O/1/M|
----------------------------------------------------------------------------------------------------------------------------------------
|   0 | SELECT STATEMENT                           |xxxxxxxx  |      1 |        |     15 |00:00:00.62 |     353K|       |       |      |
|*  1 |  FILTER                                    |xxxxxxxx  |      1 |        |     15 |00:00:00.62 |     353K|       |       |      |
|*  2 |   VIEW                                     |xxxxxxxx  |      1 |   5530 |     15 |00:00:00.62 |     353K|       |       |      |
|   3 |    SORT ORDER BY                           |xxxxxxxx  |      1 |   5530 |   7873 |00:00:00.62 |     353K|   549K|   457K| 1/0/0|
|   4 |     COUNT                                  |xxxxxxxx  |      1 |        |   7873 |00:00:00.46 |     353K|       |       |      |
|   5 |      NESTED LOOPS                          |xxxxxxxx  |      1 |   5530 |   7873 |00:00:00.46 |     353K|       |       |      |
|   6 |       NESTED LOOPS                         |xxxxxxxx  |      1 |   5530 |    266K|00:00:00.44 |     240K|       |       |      |
|   7 |        NESTED LOOPS                        |xxxxxxxx  |      1 |   5530 |    266K|00:00:00.19 |   46039 |       |       |      |
|*  8 |         TABLE ACCESS FULL                  |xxxxxxxx  |      1 |   4392 |     90 |00:00:00.01 |     878 |       |       |      |
|   9 |         TABLE ACCESS BY INDEX ROWID BATCHED|xxxxxxxx  |     90 |      1 |    266K|00:00:00.17 |   45161 |       |       |      |
|* 10 |          INDEX RANGE SCAN                  |xxxxxxxx  |     90 |      1 |    266K|00:00:00.04 |    3871 |       |       |      |
|* 11 |        INDEX UNIQUE SCAN                   |xxxxxxxx  |    266K|      1 |    266K|00:00:00.20 |     194K|       |       |      |
|* 12 |       TABLE ACCESS BY INDEX ROWID          |xxxxxxxx  |    266K|      1 |   7873 |00:00:00.20 |     113K|       |       |      |
|  13 |        TABLE ACCESS BY INDEX ROWID BATCHED |xxxxxxxx  |      1 |      1 |      1 |00:00:00.01 |       2 |       |       |      |
|* 14 |         INDEX RANGE SCAN                   |xxxxxxxx  |      1 |      1 |      1 |00:00:00.01 |       1 |       |       |      |
----------------------------------------------------------------------------------------------------------------------------------------

First talking about column ‘Starts’, that is the number of times that operation actually happened. The column with title ‘Buffers’ refers to the amount of buffer read/write (IO) performed. Now comes the column ‘OMem’, and it is the memory estimate needed to perform the operation in memory only. This is also called the optimal execution.
Next column with title ‘1Mem’ is the memory estimate needed to perform the operation in a single pass (Read/Write from disk (temp) only once), called one-pass execution. A multi-pass execution is when the same data is written to and read from disk more than once. Think about the sorting, where the database has to do a sort on large amount data in a small PGA or sort area.

Last column with title ‘0/1/M’ and sometimes ‘Used-Mem‘ is the ACTUAL amount of memory used for the operation. You also see some numbers in the brackets for this column. There is a significance for them – If the number is 0, then it was an optimal execution, used only memory and no temporary space. If the number is 1, then it was a one-pass execution. If the number is > 1, it was a multi-pass execution, and that number represents the number of passes.

Hope It Helped!
Prashant Dixit

Posted in Advanced, troubleshooting | Tagged: , , , | Leave a Comment »

Use gather_plan_statistics hint to understand optimizer’s estimations and much more ..

Posted by FatDBA on January 10, 2022

Lately someone told me that he ran the gather_plan_statistics hint with his SQL, but he is not getting the detailed execution plan, I mean all extra stats that you see i.e. starts, estimated time, starts, buffers, actual and estimated number of rows were not there and he was getting the regular/simple execution plan.

But I found he was trying it in a wrong way! The /*+ gather_plan_statistics */ hint does not save data into PLAN_TABLE, but it stores execution statistics in V$SQL_PLAN performance view. To display these data you can use (dbms_xplan.display_cursor (format=>’ALLSTATS LAST’)), but this not always work, because you must execute the second command immediately after the SQL query. The better method is to query V$SQL or V$SQLAREA or any useful view to obtain SQL_ID of the query, and then use DISPLAY_CURSOR function, for example in this way …

SQL>
SQL> SELECT /*+ gather_plan_statistics */ * FROM (SELECT A.MANDNA_KKAJ_DI,A.NAME,ROWNUM IDX FROM DIXDROI.INF_KRA_PRIMAR A,DIXDROI.INF_KRA_PRIMAR_B B,DIXDROI.INF_KRA_PRIMAR_RANGE C WHERE A.TYPE='MOBILE'
AND A.STATUS='Available' AND A.ASSIGNED_CSN_ID IS NULL AND B.OWNING_OBJECT_ID=A.MANDNA_KKAJ_DI AND
B.BINDING_NAME='com.paratapata.killer.mfs.oare.mainframe.locking.ADAKingstonToKillerRangeStst' AND C.MANDNA_KKAJ_DI=B.TARGET_OBJECT_ID
AND C.STATUS = NVL('Active', C.STATUS) AND C.CATEGORY = 'Range'
AND 'Internal' = NVL(C.NUMBER_USAGE,'External') AND (A.lock_id IS NULL OR A.LOCK_DATE <= (sysdate - NVL(A.LOCK_PERIOD,(SELECT mark_raar_value 
FROM DIXDROI.PAM_KRIAIS_MAINFATRAARA_AHAH WHERE mark_raar_name = 'DEFAULT_LOCK_PERIOD' )) / 60 / 24))
ORDER BY TO_NUMBER(A.NAME) ) RESULTS WHERE RESULTS.IDX BETWEEN 1 AND 15; 

MANDNA_KKAJ_DI NAME                                                      IDX
-------------- -------------------------------------------------- ----------
      91891302 0444915115                                                 12
      91891309 0444915122                                                 13
      91891310 0444915123                                                 14
      91891314 0444915127                                                 15
      91891723 0444915536                                                  2
      91891724 0444915537                                                  3
      91891726 0444915539                                                  4
      91891730 0444915543                                                  5
      91891739 0444915552                                                  6
      91891748 0444915561                                                  7
      91891766 0444915579                                                  8
      91891768 0444915581                                                  9
      91891807 0444915620                                                 10
      91891854 0444915667                                                 11
      17116808 04466962472                                                 1

15 rows selected.

SQL> select sql_id, plan_hash_value, executions, sql_text from gv$sqlarea where sql_fulltext like '%gather_plan_statistics%';

SQL_ID        PLAN_HASH_VALUE EXECUTIONS SQL_TEXT
------------- --------------- ---------- ------------------------------------------------------------
0m329sngnhv1p      2185860753          1 SELECT /*+ gather_plan_statistics */ * FROM (SELECT A.OBJECT
                                         _INST_ID,A.NAME,ROWNUM IDX FROM DIXDROI.INF_KRA_PRIMAR A,INS
                                         TALL.INF_KRA_PRIMAR_B B,DIXDROI.INF_KRA_PRIMAR_RANGE C WHERE
                                          A.TYPE=:"SYS_B_00" AND A.STATUS=:"SYS_B_01" AND A.ASSIGNED_
                                         CSN_ID IS NULL AND B.OWNING_OBJECT_ID=A.MANDNA_KKAJ_DI AND B
                                         .BINDING_NAME=:"SYS_B_02" AND C.MANDNA_KKAJ_DI=B.TARGET_OBJE
                                         CT_ID AND C.STATUS = NVL(:"SYS_B_03", C.STATUS) AND C.CATEGO
                                         RY = :"SYS_B_04" AND :"SYS_B_05" = NVL(C.NUMBER_USAGE,:"SYS_
                                         B_06") AND (A.lock_id IS NULL OR A.LOCK_DATE <= (sysdate - N
                                         VL(A.LOCK_PERIOD,(SELECT mark_raar_value FROM DIXDROI.EAI_HY
                                         BRIS_CONFIGURATION_DATA WHERE mark_raar_name = :"SYS_B_07" )
                                         ) / :"SYS_B_08" / :"SYS_B_09")) ORDER BY TO_NUMBER(A.NAME) )
                                          RESULTS WHERE RESULTS.IDX BETWEEN :"SYS_B_10" AND :"SYS_B_1
                                         1"

The above query returns SQL_ID=0m329sngnhv1p and CHILD_NUMBER=0(child number is just a cursor number). Use these values to query the collected plan. This will show you statistics such as the actual number of rows processed (A-Rows), rather than just the estimates (E-Rows). A-Rows is the total number of rows produced by all starts of that operation. But E-Rows is an estimate of the number of rows produced by a single start of an operation. If you want to read about E-Rows and A-Rows columns, please read a brilliant post by Jonathan Lewis.

Okay, the plan also includes a column called Starts, which tells you how many times each step was executed. A-Rows, E-Rows and Starts are all incredibly useful if you want to understand a plan.

SQL> SELECT * FROM table(DBMS_XPLAN.DISPLAY_CURSOR('0m329sngnhv1p', 0, 'ALLSTATS'));

PLAN_TABLE_OUTPUT
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
SQL_ID  0m329sngnhv1p, child number 0
-------------------------------------
SELECT /*+ gather_plan_statistics */ * FROM (SELECT
A.MANDNA_KKAJ_DI,A.NAME,ROWNUM IDX FROM DIXDROI.INF_KRA_PRIMAR
A,DIXDROI.INF_KRA_PRIMAR_B B,DIXDROI.INF_KRA_PRIMAR_RANGE C WHERE
A.TYPE=:"SYS_B_00" AND A.STATUS=:"SYS_B_01" AND A.ASSIGNED_CSN_ID IS
NULL AND B.OWNING_OBJECT_ID=A.MANDNA_KKAJ_DI AND
B.BINDING_NAME=:"SYS_B_02" AND C.MANDNA_KKAJ_DI=B.TARGET_OBJECT_ID AND
C.STATUS = NVL(:"SYS_B_03", C.STATUS) AND C.CATEGORY = :"SYS_B_04" AND
:"SYS_B_05" = NVL(C.NUMBER_USAGE,:"SYS_B_06") AND (A.lock_id IS NULL OR
A.LOCK_DATE <= (sysdate - NVL(A.LOCK_PERIOD,(SELECT mark_raar_value
FROM DIXDROI.PAM_KRIAIS_MAINFATRAARA_AHAH WHERE mark_raar_name =
:"SYS_B_07" )) / :"SYS_B_08" / :"SYS_B_09")) ORDER BY TO_NUMBER(A.NAME)
) RESULTS WHERE RESULTS.IDX BETWEEN :"SYS_B_10" AND :"SYS_B_11"


Plan hash value: 2185860753


-----------------------------------------------------------------------------------------------------------------------------------------------------------------
| Id  | Operation                                  | Name                          | Starts | E-Rows | A-Rows |   A-Time   | Buffers |  OMem |  1Mem |  O/1/M|
-----------------------------------------------------------------------------------------------------------------------------------------------------------------
|   0 | SELECT STATEMENT                           |                               |      1 |        |     15 |00:00:00.62 |     353K|       |       |      |
|*  1 |  FILTER                                    |                               |      1 |        |     15 |00:00:00.62 |     353K|       |       |      |
|*  2 |   VIEW                                     |                               |      1 |   5530 |     15 |00:00:00.62 |     353K|       |       |      |
|   3 |    SORT ORDER BY                           |                               |      1 |   5530 |   7873 |00:00:00.62 |     353K|   549K|   457K| 1/0/0|
|   4 |     COUNT                                  |                               |      1 |        |   7873 |00:00:00.46 |     353K|       |       |      |
|   5 |      NESTED LOOPS                          |                               |      1 |   5530 |   7873 |00:00:00.46 |     353K|       |       |      |
|   6 |       NESTED LOOPS                         |                               |      1 |   5530 |    266K|00:00:00.44 |     240K|       |       |      |
|   7 |        NESTED LOOPS                        |                               |      1 |   5530 |    266K|00:00:00.19 |   46039 |       |       |      |
|*  8 |         TABLE ACCESS FULL                  | INF_KRA_PRIMAR_RANGE          |      1 |   4392 |     90 |00:00:00.01 |     878 |       |       |      |
|   9 |         TABLE ACCESS BY INDEX ROWID BATCHED| INF_KRA_PRIMAR_B              |     90 |      1 |    266K|00:00:00.17 |   45161 |       |       |      |
|* 10 |          INDEX RANGE SCAN                  | EAI_NUMBER_REL_1              |     90 |      1 |    266K|00:00:00.04 |    3871 |       |       |      |
|* 11 |        INDEX UNIQUE SCAN                   | PK_INF_KRA_PRIMAR             |    266K|      1 |    266K|00:00:00.20 |     194K|       |       |      |
|* 12 |       TABLE ACCESS BY INDEX ROWID          | INF_KRA_PRIMAR                |    266K|      1 |   7873 |00:00:00.20 |     113K|       |       |      |
|  13 |        TABLE ACCESS BY INDEX ROWID BATCHED | PAM_KRIAIS_MAINFATRAARA_AHAH  |      1 |      1 |      1 |00:00:00.01 |       2 |       |       |      |
|* 14 |         INDEX RANGE SCAN                   | IDXGETNUMBERPD1               |      1 |      1 |      1 |00:00:00.01 |       1 |       |       |      |
-----------------------------------------------------------------------------------------------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

   1 - filter(:SYS_B_11>=:SYS_B_10)
   2 - filter(("RESULTS"."IDX">=:SYS_B_10 AND "RESULTS"."IDX"<=:SYS_B_11))
   8 - filter((NVL("C"."CATEGORY",'Range')=:SYS_B_04 AND NVL("C"."NUMBER_USAGE",:SYS_B_06)=:SYS_B_05 AND "C"."STATUS"=NVL(:SYS_B_03,"C"."STATUS")))
  10 - access("C"."MANDNA_KKAJ_DI"="B"."TARGET_OBJECT_ID" AND "B"."BINDING_NAME"=:SYS_B_02)
  11 - access("B"."OWNING_OBJECT_ID"="A"."MANDNA_KKAJ_DI")
  12 - filter(("A"."TYPE"=:SYS_B_00 AND "A"."STATUS"=:SYS_B_01 AND "A"."ASSIGNED_CSN_ID" IS NULL AND ("A"."LOCK_ID" IS NULL OR
              "A"."LOCK_DATE"<=SYSDATE@!-NVL("A"."LOCK_PERIOD",)/:SYS_B_08/:SYS_B_09)))
  14 - access("mark_raar_NAME"=:SYS_B_07)


49 rows selected.


There are multiple other ways how you can add or remove more details to your execution plan, lets take a look on few of those methods.

-- To get additional COST and BYTES column into plan

SQL> SELECT * FROM TABLE(DBMS_XPLAN.display_cursor(sql_id=>'0m329sngnhv1p',format=>'ALLSTATS LAST +cost +bytes'));

PLAN_TABLE_OUTPUT
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
SQL_ID  0m329sngnhv1p, child number 0
-------------------------------------
SELECT /*+ gather_plan_statistics */ * FROM (SELECT
A.MANDNA_KKAJ_DI,A.NAME,ROWNUM IDX FROM DIXDROI.INF_KRA_PRIMAR
A,DIXDROI.INF_KRA_PRIMAR_B B,DIXDROI.INF_KRA_PRIMAR_RANGE C WHERE
A.TYPE=:"SYS_B_00" AND A.STATUS=:"SYS_B_01" AND A.ASSIGNED_CSN_ID IS
NULL AND B.OWNING_OBJECT_ID=A.MANDNA_KKAJ_DI AND
B.BINDING_NAME=:"SYS_B_02" AND C.MANDNA_KKAJ_DI=B.TARGET_OBJECT_ID AND
C.STATUS = NVL(:"SYS_B_03", C.STATUS) AND C.CATEGORY = :"SYS_B_04" AND
:"SYS_B_05" = NVL(C.NUMBER_USAGE,:"SYS_B_06") AND (A.lock_id IS NULL OR
A.LOCK_DATE <= (sysdate - NVL(A.LOCK_PERIOD,(SELECT mark_raar_value
FROM DIXDROI.PAM_KRIAIS_MAINFATRAARA_AHAH WHERE mark_raar_name =
:"SYS_B_07" )) / :"SYS_B_08" / :"SYS_B_09")) ORDER BY TO_NUMBER(A.NAME)
) RESULTS WHERE RESULTS.IDX BETWEEN :"SYS_B_10" AND :"SYS_B_11"

Plan hash value: 2185860753

----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| Id  | Operation                                  | Name                          | Starts | E-Rows |E-Bytes|E-Temp | Cost (%CPU)| A-Rows |   A-Time   | Buffers |  OMem |  1Mem | Used-Mem |
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|   0 | SELECT STATEMENT                           |                               |      1 |        |       |       |  3753 (100)|     15 |00:00:00.62 |     353K|       |       |          |
|*  1 |  FILTER                                    |                               |      1 |        |       |       |            |     15 |00:00:00.62 |     353K|       |       |          |
|*  2 |   VIEW                                     |                               |      1 |   5530 |   286K|       |  3753   (1)|     15 |00:00:00.62 |     353K|       |       |          |
|   3 |    SORT ORDER BY                           |                               |      1 |   5530 |   918K|  1064K|  3753   (1)|   7873 |00:00:00.62 |     353K|   549K|   457K|  487K (0)|
|   4 |     COUNT                                  |                               |      1 |        |       |       |            |   7873 |00:00:00.46 |     353K|       |       |          |
|   5 |      NESTED LOOPS                          |                               |      1 |   5530 |   918K|       |  3544   (1)|   7873 |00:00:00.46 |     353K|       |       |          |
|   6 |       NESTED LOOPS                         |                               |      1 |   5530 |   918K|       |  3544   (1)|    266K|00:00:00.44 |     240K|       |       |          |
|   7 |        NESTED LOOPS                        |                               |      1 |   5530 |   615K|       |  2437   (1)|    266K|00:00:00.19 |   46039 |       |       |          |
|*  8 |         TABLE ACCESS FULL                  | INF_KRA_PRIMAR_RANGE          |      1 |   4392 | 92232 |       |   240   (1)|     90 |00:00:00.01 |     878 |       |       |          |
|   9 |         TABLE ACCESS BY INDEX ROWID BATCHED| INF_KRA_PRIMAR_B              |     90 |      1 |    93 |       |     1   (0)|    266K|00:00:00.17 |   45161 |       |       |          |
|* 10 |          INDEX RANGE SCAN                  | EAI_NUMBER_REL_1              |     90 |      1 |       |       |     1   (0)|    266K|00:00:00.04 |    3871 |       |       |          |
|* 11 |        INDEX UNIQUE SCAN                   | PK_INF_KRA_PRIMAR             |    266K|      1 |       |       |     1   (0)|    266K|00:00:00.20 |     194K|       |       |          |
|* 12 |       TABLE ACCESS BY INDEX ROWID          | INF_KRA_PRIMAR                |    266K|      1 |    56 |       |     1   (0)|   7873 |00:00:00.20 |     113K|       |       |          |
|  13 |        TABLE ACCESS BY INDEX ROWID BATCHED | PAM_KRIAIS_MAINFATRAARA_AHAH  |      1 |      1 |    28 |       |     1   (0)|      1 |00:00:00.01 |       2 |       |       |          |
|* 14 |         INDEX RANGE SCAN                   | IDXGETNUMBERPD1               |      1 |      1 |       |       |     1   (0)|      1 |00:00:00.01 |       1 |       |       |          |
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

   1 - filter(:SYS_B_11>=:SYS_B_10)
   2 - filter(("RESULTS"."IDX">=:SYS_B_10 AND "RESULTS"."IDX"<=:SYS_B_11))
   8 - filter((NVL("C"."CATEGORY",'Range')=:SYS_B_04 AND NVL("C"."NUMBER_USAGE",:SYS_B_06)=:SYS_B_05 AND "C"."STATUS"=NVL(:SYS_B_03,"C"."STATUS")))
  10 - access("C"."MANDNA_KKAJ_DI"="B"."TARGET_OBJECT_ID" AND "B"."BINDING_NAME"=:SYS_B_02)
  11 - access("B"."OWNING_OBJECT_ID"="A"."MANDNA_KKAJ_DI")
  12 - filter(("A"."TYPE"=:SYS_B_00 AND "A"."STATUS"=:SYS_B_01 AND "A"."ASSIGNED_CSN_ID" IS NULL AND ("A"."LOCK_ID" IS NULL OR
              "A"."LOCK_DATE"<=SYSDATE@!-NVL("A"."LOCK_PERIOD",)/:SYS_B_08/:SYS_B_09)))
  14 - access("mark_raar_NAME"=:SYS_B_07)


49 rows selected.







-- To get OUTLINE data into your execution plan

SQL>
SQL> SELECT * FROM TABLE(DBMS_XPLAN.display_cursor(sql_id=>'0m329sngnhv1p', format=>'ALLSTATS LAST +outline'));

PLAN_TABLE_OUTPUT
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
SQL_ID  0m329sngnhv1p, child number 0
-------------------------------------
SELECT /*+ gather_plan_statistics */ * FROM (SELECT
A.MANDNA_KKAJ_DI,A.NAME,ROWNUM IDX FROM DIXDROI.INF_KRA_PRIMAR
A,DIXDROI.INF_KRA_PRIMAR_B B,DIXDROI.INF_KRA_PRIMAR_RANGE C WHERE
A.TYPE=:"SYS_B_00" AND A.STATUS=:"SYS_B_01" AND A.ASSIGNED_CSN_ID IS
NULL AND B.OWNING_OBJECT_ID=A.MANDNA_KKAJ_DI AND
B.BINDING_NAME=:"SYS_B_02" AND C.MANDNA_KKAJ_DI=B.TARGET_OBJECT_ID AND
C.STATUS = NVL(:"SYS_B_03", C.STATUS) AND C.CATEGORY = :"SYS_B_04" AND
:"SYS_B_05" = NVL(C.NUMBER_USAGE,:"SYS_B_06") AND (A.lock_id IS NULL OR
A.LOCK_DATE <= (sysdate - NVL(A.LOCK_PERIOD,(SELECT mark_raar_value
FROM DIXDROI.PAM_KRIAIS_MAINFATRAARA_AHAH WHERE mark_raar_name =
:"SYS_B_07" )) / :"SYS_B_08" / :"SYS_B_09")) ORDER BY TO_NUMBER(A.NAME)
) RESULTS WHERE RESULTS.IDX BETWEEN :"SYS_B_10" AND :"SYS_B_11"

Plan hash value: 2185860753

-----------------------------------------------------------------------------------------------------------------------------------------------------------------
| Id  | Operation                                  | Name                          | Starts | E-Rows | A-Rows |   A-Time   | Buffers |  OMem |  1Mem | Used-Mem |
-----------------------------------------------------------------------------------------------------------------------------------------------------------------
|   0 | SELECT STATEMENT                           |                               |      1 |        |     15 |00:00:00.62 |     353K|       |       |          |
|*  1 |  FILTER                                    |                               |      1 |        |     15 |00:00:00.62 |     353K|       |       |          |
|*  2 |   VIEW                                     |                               |      1 |   5530 |     15 |00:00:00.62 |     353K|       |       |          |
|   3 |    SORT ORDER BY                           |                               |      1 |   5530 |   7873 |00:00:00.62 |     353K|   549K|   457K|  487K (0)|
|   4 |     COUNT                                  |                               |      1 |        |   7873 |00:00:00.46 |     353K|       |       |          |
|   5 |      NESTED LOOPS                          |                               |      1 |   5530 |   7873 |00:00:00.46 |     353K|       |       |          |
|   6 |       NESTED LOOPS                         |                               |      1 |   5530 |    266K|00:00:00.44 |     240K|       |       |          |
|   7 |        NESTED LOOPS                        |                               |      1 |   5530 |    266K|00:00:00.19 |   46039 |       |       |          |
|*  8 |         TABLE ACCESS FULL                  | INF_KRA_PRIMAR_RANGE          |      1 |   4392 |     90 |00:00:00.01 |     878 |       |       |          |
|   9 |         TABLE ACCESS BY INDEX ROWID BATCHED| INF_KRA_PRIMAR_B              |     90 |      1 |    266K|00:00:00.17 |   45161 |       |       |          |
|* 10 |          INDEX RANGE SCAN                  | EAI_NUMBER_REL_1              |     90 |      1 |    266K|00:00:00.04 |    3871 |       |       |          |
|* 11 |        INDEX UNIQUE SCAN                   | PK_INF_KRA_PRIMAR             |    266K|      1 |    266K|00:00:00.20 |     194K|       |       |          |
|* 12 |       TABLE ACCESS BY INDEX ROWID          | INF_KRA_PRIMAR                |    266K|      1 |   7873 |00:00:00.20 |     113K|       |       |          |
|  13 |        TABLE ACCESS BY INDEX ROWID BATCHED | PAM_KRIAIS_MAINFATRAARA_AHAH  |      1 |      1 |      1 |00:00:00.01 |       2 |       |       |          |
|* 14 |         INDEX RANGE SCAN                   | IDXGETNUMBERPD1               |      1 |      1 |      1 |00:00:00.01 |       1 |       |       |          |
-----------------------------------------------------------------------------------------------------------------------------------------------------------------

Outline Data
-------------

  /*+
      BEGIN_OUTLINE_DATA
      IGNORE_OPTIM_EMBEDDED_HINTS
      OPTIMIZER_FEATURES_ENABLE('12.2.0.1')
      DB_VERSION('12.2.0.1')
      OPT_PARAM('optimizer_index_cost_adj' 10)
      FIRST_ROWS(1)
      OUTLINE_LEAF(@"SEL$3")
      OUTLINE_LEAF(@"SEL$2")
      OUTLINE_LEAF(@"SEL$1")
      NO_ACCESS(@"SEL$1" "RESULTS"@"SEL$1")
      FULL(@"SEL$2" "C"@"SEL$2")
      INDEX_RS_ASC(@"SEL$2" "B"@"SEL$2" ("INF_KRA_PRIMAR_B"."TARGET_OBJECT_ID" "INF_KRA_PRIMAR_B"."BINDING_NAME"))
      BATCH_TABLE_ACCESS_BY_ROWID(@"SEL$2" "B"@"SEL$2")
      INDEX(@"SEL$2" "A"@"SEL$2" ("INF_KRA_PRIMAR"."MANDNA_KKAJ_DI"))
      LEADING(@"SEL$2" "C"@"SEL$2" "B"@"SEL$2" "A"@"SEL$2")
      USE_NL(@"SEL$2" "B"@"SEL$2")
      USE_NL(@"SEL$2" "A"@"SEL$2")
      NLJ_BATCHING(@"SEL$2" "A"@"SEL$2")
      PUSH_SUBQ(@"SEL$3")
      INDEX_RS_ASC(@"SEL$3" "PAM_KRIAIS_MAINFATRAARA_AHAH"@"SEL$3" ("PAM_KRIAIS_MAINFATRAARA_AHAH"."mark_raar_NAME"))
      BATCH_TABLE_ACCESS_BY_ROWID(@"SEL$3" "PAM_KRIAIS_MAINFATRAARA_AHAH"@"SEL$3")
      END_OUTLINE_DATA
  */

Predicate Information (identified by operation id):
---------------------------------------------------

   1 - filter(:SYS_B_11>=:SYS_B_10)
   2 - filter(("RESULTS"."IDX">=:SYS_B_10 AND "RESULTS"."IDX"<=:SYS_B_11))
   8 - filter((NVL("C"."CATEGORY",'Range')=:SYS_B_04 AND NVL("C"."NUMBER_USAGE",:SYS_B_06)=:SYS_B_05 AND "C"."STATUS"=NVL(:SYS_B_03,"C"."STATUS")))
  10 - access("C"."MANDNA_KKAJ_DI"="B"."TARGET_OBJECT_ID" AND "B"."BINDING_NAME"=:SYS_B_02)
  11 - access("B"."OWNING_OBJECT_ID"="A"."MANDNA_KKAJ_DI")
  12 - filter(("A"."TYPE"=:SYS_B_00 AND "A"."STATUS"=:SYS_B_01 AND "A"."ASSIGNED_CSN_ID" IS NULL AND ("A"."LOCK_ID" IS NULL OR
              "A"."LOCK_DATE"<=SYSDATE@!-NVL("A"."LOCK_PERIOD",)/:SYS_B_08/:SYS_B_09)))
  14 - access("mark_raar_NAME"=:SYS_B_07)


77 rows selected.

SQL>







-- Lets try a more sophisticated one to get all sorts of information available

SQL>
SQL>
SQL> SELECT * FROM TABLE(dbms_xplan.display_cursor(sql_id => '0m329sngnhv1p', FORMAT => 'ADVANCED +ROWS +BYTES +COST +PARALLEL +PARTITION +IOSTATS +MEMSTATS +ALIAS +PEEKED_BINDS +OUTLINE +PREDICATE +PROJECTION +REMOTE +NOTE'));

PLAN_TABLE_OUTPUT
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
SQL_ID  0m329sngnhv1p, child number 0
-------------------------------------
SELECT /*+ gather_plan_statistics */ * FROM (SELECT
A.MANDNA_KKAJ_DI,A.NAME,ROWNUM IDX FROM DIXDROI.INF_KRA_PRIMAR
A,DIXDROI.INF_KRA_PRIMAR_B B,DIXDROI.INF_KRA_PRIMAR_RANGE C WHERE
A.TYPE=:"SYS_B_00" AND A.STATUS=:"SYS_B_01" AND A.ASSIGNED_CSN_ID IS
NULL AND B.OWNING_OBJECT_ID=A.MANDNA_KKAJ_DI AND
B.BINDING_NAME=:"SYS_B_02" AND C.MANDNA_KKAJ_DI=B.TARGET_OBJECT_ID AND
C.STATUS = NVL(:"SYS_B_03", C.STATUS) AND C.CATEGORY = :"SYS_B_04" AND
:"SYS_B_05" = NVL(C.NUMBER_USAGE,:"SYS_B_06") AND (A.lock_id IS NULL OR
A.LOCK_DATE <= (sysdate - NVL(A.LOCK_PERIOD,(SELECT mark_raar_value
FROM DIXDROI.PAM_KRIAIS_MAINFATRAARA_AHAH WHERE mark_raar_name =
:"SYS_B_07" )) / :"SYS_B_08" / :"SYS_B_09")) ORDER BY TO_NUMBER(A.NAME)
) RESULTS WHERE RESULTS.IDX BETWEEN :"SYS_B_10" AND :"SYS_B_11"

Plan hash value: 2185860753

---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| Id  | Operation                                  | Name                          | Starts | E-Rows |E-Bytes|E-Temp | Cost (%CPU)| E-Time   | A-Rows |   A-Time   | Buffers |  OMem |  1Mem |  O/1/M   |
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|   0 | SELECT STATEMENT                           |                               |      1 |        |       |       |  3753 (100)|          |     15 |00:00:00.62 |     353K|       |       |          |
|*  1 |  FILTER                                    |                               |      1 |        |       |       |            |          |     15 |00:00:00.62 |     353K|       |       |          |
|*  2 |   VIEW                                     |                               |      1 |   5530 |   286K|       |  3753   (1)| 00:00:01 |     15 |00:00:00.62 |     353K|       |       |          |
|   3 |    SORT ORDER BY                           |                               |      1 |   5530 |   918K|  1064K|  3753   (1)| 00:00:01 |   7873 |00:00:00.62 |     353K|   549K|   457K|     1/0/0|
|   4 |     COUNT                                  |                               |      1 |        |       |       |            |          |   7873 |00:00:00.46 |     353K|       |       |          |
|   5 |      NESTED LOOPS                          |                               |      1 |   5530 |   918K|       |  3544   (1)| 00:00:01 |   7873 |00:00:00.46 |     353K|       |       |          |
|   6 |       NESTED LOOPS                         |                               |      1 |   5530 |   918K|       |  3544   (1)| 00:00:01 |    266K|00:00:00.44 |     240K|       |       |          |
|   7 |        NESTED LOOPS                        |                               |      1 |   5530 |   615K|       |  2437   (1)| 00:00:01 |    266K|00:00:00.19 |    46039|       |       |          |
|*  8 |         TABLE ACCESS FULL                  | INF_KRA_PRIMAR_RANGE          |      1 |   4392 | 92232 |       |   240   (1)| 00:00:01 |     90 |00:00:00.01 |      878|       |       |          |
|   9 |         TABLE ACCESS BY INDEX ROWID BATCHED| INF_KRA_PRIMAR_B              |     90 |      1 |    93 |       |     1   (0)| 00:00:01 |    266K|00:00:00.17 |    45161|       |       |          |
|* 10 |          INDEX RANGE SCAN                  | EAI_NUMBER_REL_1              |     90 |      1 |       |       |     1   (0)| 00:00:01 |    266K|00:00:00.04 |     3871|       |       |          |
|* 11 |        INDEX UNIQUE SCAN                   | PK_INF_KRA_PRIMAR             |    266K|      1 |       |       |     1   (0)| 00:00:01 |    266K|00:00:00.20 |     194K|       |       |          |
|* 12 |       TABLE ACCESS BY INDEX ROWID          | INF_KRA_PRIMAR                |    266K|      1 |    56 |       |     1   (0)| 00:00:01 |   7873 |00:00:00.20 |     113K|       |       |          |
|  13 |        TABLE ACCESS BY INDEX ROWID BATCHED | PAM_KRIAIS_MAINFATRAARA_AHAH  |      1 |      1 |    28 |       |     1   (0)| 00:00:01 |      1 |00:00:00.01 |        2|       |       |          |
|* 14 |         INDEX RANGE SCAN                   | IDXGETNUMBERPD1               |      1 |      1 |       |       |     1   (0)| 00:00:01 |      1 |00:00:00.01 |        1|       |       |          |
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Query Block Name / Object Alias (identified by operation id):
-------------------------------------------------------------

   1 - SEL$1
   2 - SEL$2 / RESULTS@SEL$1
   3 - SEL$2
   8 - SEL$2 / C@SEL$2
   9 - SEL$2 / B@SEL$2
  10 - SEL$2 / B@SEL$2
  11 - SEL$2 / A@SEL$2
  12 - SEL$2 / A@SEL$2
  13 - SEL$3 / PAM_KRIAIS_MAINFATRAARA_AHAH@SEL$3
  14 - SEL$3 / PAM_KRIAIS_MAINFATRAARA_AHAH@SEL$3

Outline Data
-------------

  /*+
      BEGIN_OUTLINE_DATA
      IGNORE_OPTIM_EMBEDDED_HINTS
      OPTIMIZER_FEATURES_ENABLE('12.2.0.1')
      DB_VERSION('12.2.0.1')
      OPT_PARAM('optimizer_index_cost_adj' 10)
      FIRST_ROWS(1)
      OUTLINE_LEAF(@"SEL$3")
      OUTLINE_LEAF(@"SEL$2")
      OUTLINE_LEAF(@"SEL$1")
      NO_ACCESS(@"SEL$1" "RESULTS"@"SEL$1")
      FULL(@"SEL$2" "C"@"SEL$2")
      INDEX_RS_ASC(@"SEL$2" "B"@"SEL$2" ("INF_KRA_PRIMAR_B"."TARGET_OBJECT_ID" "INF_KRA_PRIMAR_B"."BINDING_NAME"))
      BATCH_TABLE_ACCESS_BY_ROWID(@"SEL$2" "B"@"SEL$2")
      INDEX(@"SEL$2" "A"@"SEL$2" ("INF_KRA_PRIMAR"."MANDNA_KKAJ_DI"))
      LEADING(@"SEL$2" "C"@"SEL$2" "B"@"SEL$2" "A"@"SEL$2")
      USE_NL(@"SEL$2" "B"@"SEL$2")
      USE_NL(@"SEL$2" "A"@"SEL$2")
      NLJ_BATCHING(@"SEL$2" "A"@"SEL$2")
      PUSH_SUBQ(@"SEL$3")
      INDEX_RS_ASC(@"SEL$3" "PAM_KRIAIS_MAINFATRAARA_AHAH"@"SEL$3" ("PAM_KRIAIS_MAINFATRAARA_AHAH"."mark_raar_NAME"))
      BATCH_TABLE_ACCESS_BY_ROWID(@"SEL$3" "PAM_KRIAIS_MAINFATRAARA_AHAH"@"SEL$3")
      END_OUTLINE_DATA
  */

Peeked Binds (identified by position):
--------------------------------------

   1 - :1 (VARCHAR2(30), CSID=873): 'MOBILE'
   2 - :2 (VARCHAR2(30), CSID=873): 'Available'
   3 - (VARCHAR2(30), CSID=873): 'com.paratapata.killer.mfs.oare.mainframe.locking.ADAKingstonToKillerRangeStst'
   4 - (VARCHAR2(30), CSID=873): 'Active'
   5 - (VARCHAR2(30), CSID=873): 'Range'
   6 - (VARCHAR2(30), CSID=873): 'Internal'
   7 - (VARCHAR2(30), CSID=873): 'External'

Predicate Information (identified by operation id):
---------------------------------------------------

   1 - filter(:SYS_B_11>=:SYS_B_10)
   2 - filter(("RESULTS"."IDX">=:SYS_B_10 AND "RESULTS"."IDX"<=:SYS_B_11))
   8 - filter((NVL("C"."CATEGORY",'Range')=:SYS_B_04 AND NVL("C"."NUMBER_USAGE",:SYS_B_06)=:SYS_B_05 AND "C"."STATUS"=NVL(:SYS_B_03,"C"."STATUS")))
  10 - access("C"."MANDNA_KKAJ_DI"="B"."TARGET_OBJECT_ID" AND "B"."BINDING_NAME"=:SYS_B_02)
  11 - access("B"."OWNING_OBJECT_ID"="A"."MANDNA_KKAJ_DI")
  12 - filter(("A"."TYPE"=:SYS_B_00 AND "A"."STATUS"=:SYS_B_01 AND "A"."ASSIGNED_CSN_ID" IS NULL AND ("A"."LOCK_ID" IS NULL OR
              "A"."LOCK_DATE"<=SYSDATE@!-NVL("A"."LOCK_PERIOD",)/:SYS_B_08/:SYS_B_09)))
  14 - access("mark_raar_NAME"=:SYS_B_07)

Column Projection Information (identified by operation id):
-----------------------------------------------------------

   1 - "RESULTS"."MANDNA_KKAJ_DI"[NUMBER,22], "RESULTS"."NAME"[VARCHAR2,50], "RESULTS"."IDX"[NUMBER,22]
   2 - "RESULTS"."MANDNA_KKAJ_DI"[NUMBER,22], "RESULTS"."NAME"[VARCHAR2,50], "RESULTS"."IDX"[NUMBER,22]
   3 - (#keys=1) TO_NUMBER("NAME")[22], "A"."MANDNA_KKAJ_DI"[NUMBER,22], "A"."NAME"[VARCHAR2,50], ROWNUM[22]
   4 - "A"."MANDNA_KKAJ_DI"[NUMBER,22], "NAME"[VARCHAR2,50], ROWNUM[8]
   5 - "A"."MANDNA_KKAJ_DI"[NUMBER,22], "NAME"[VARCHAR2,50]
   6 - "A".ROWID[ROWID,10], "A"."MANDNA_KKAJ_DI"[NUMBER,22]
   7 - "B"."OWNING_OBJECT_ID"[NUMBER,22]
   8 - "C"."MANDNA_KKAJ_DI"[NUMBER,22]
   9 - "B"."OWNING_OBJECT_ID"[NUMBER,22]
  10 - "B".ROWID[ROWID,10]
  11 - "A".ROWID[ROWID,10], "A"."MANDNA_KKAJ_DI"[NUMBER,22]
  12 - "NAME"[VARCHAR2,50]
  13 - "mark_raar_VALUE"[NUMBER,22]
  14 - "PAM_KRIAIS_MAINFATRAARA_AHAH".ROWID[ROWID,10]


120 rows selected.

SQL>

Hope It Helped!
Prashant Dixit

Posted in Advanced, troubleshooting | Tagged: , , , , , | 1 Comment »

ORA-12034: materialized view log younger than last refresh

Posted by FatDBA on January 7, 2022

Recently I have encountered an issue where frequent errors were captured in the alert log file about the on demand materialized view refresh failure. The main error reported was ORA-12034: materialized view log on “DIXDROID”.”TEST_STATS” younger than last refresh.

On demand
MV DIXDROID.PRAS_ID_MV was not refreshed successfully.
Number of MV refresh failures: 1.
Encountered error ORA-12034.
kkzifr3g: Encountered error ORA-12034.
2022-01-06T11:14:49.885045+02:00
Errors in file /monkeydb/can/ontadb/rdbms/ontadb/ONTADB/trace/ONTADB_j000_5663.trc:
ORA-12012: error on auto execute of job 1
ORA-12034: materialized view log on "DIXDROID"."TEST_STATS" younger than last refresh
ORA-06512: at "SYS.DBMS_SNAPSHOT_KKXRCA", line 2960
ORA-06512: at "SYS.DBMS_SNAPSHOT_KKXRCA", line 2378
ORA-06512: at "SYS.DBMS_SNAPSHOT_KKXRCA", line 85
ORA-06512: at "SYS.DBMS_SNAPSHOT_KKXRCA", line 245
ORA-06512: at "SYS.DBMS_SNAPSHOT_KKXRCA", line 2360
ORA-06512: at "SYS.DBMS_SNAPSHOT_KKXRCA", line 2916
ORA-06512: at "SYS.DBMS_SNAPSHOT_KKXRCA", line 3199
ORA-06512: at "SYS.DBMS_SNAPSHOT_KKXRCA", line 3255
ORA-06512: at "SYS.DBMS_SNAPSHOT", line 41
ORA-06512: at "SYS.DBMS_IREFRESH", line 703
ORA-06512: at "SYS.DBMS_REFRESH", line 214
ORA-06512: at line 1

It was pointing to the Materialized View Log, about materialized view logs, they are created for a master table, and a materialized view has been created with the REFRESH FAST option, the following timestamps will be used when validating log age.

About potential causes, there could be many i.e.

  • Definition of the master table is altered.
  • The last refresh was failed for some reasons.
  • Altering the master table so that changes don’t go to the materialized view log i.e. truncate, alter partitions drop or truncate
  • Master table reorganization or when when issuing an MV log purge

Now about the solution, in our case this issue happens when a complete refresh is required before the next fast refresh. So I did the COMPLETE refresh for the MV in question and did the FAST refresh soon after that and that has fixed the issue.

SQL*Plus: Release 12.2.0.1.0 Production on Thu Jan 6 11:14:07 2022

Copyright (c) 1982, 2016, Oracle.  All rights reserved.

Enter user-name: / as sysdba

Connected to:
Oracle Database 12c Enterprise Edition Release 12.2.0.1.0 - 64bit Production

SQL>

-- Following command will perform first time COMPLETE refresh on the materialized views
SQL> execute dbms_snapshot.refresh ('DIXDROID.PRAS_ID_MV', 'C');

PL/SQL procedure successfully completed.

-- After this first time COMPLETE refresh, the successive FAST refresh will be successful.
SQL> execute dbms_snapshot.refresh ('DIXDROID.PRAS_ID_MV', 'F');

PL/SQL procedure successfully completed.

SQL>

Hope It Helped!
Prashant Dixit

Posted in troubleshooting | Tagged: , | Leave a Comment »

Getting SQL ID in advance, before the real execution, possible ?

Posted by FatDBA on January 4, 2022

Happy New Year Everyone!

Starting 2022 with a short and a quick post! 🙂

Today, one of the customer’s application architect during a team meet asked me if its possible to have the SQL ID in advance, before the SQL execution ? And luckily, I know that’s possible (through Connor McDonald‘s blog post on the same subject) and I was immediately able to answer the customer with a confident ‘Yes, that’s possible!’ 🙂

When I asked, why he want to do that, he said that they are planning to integrate a new module to their CRM application, first into development environment where they want to catch all expensive SQLs, their IDs in advance and later on compare it with the UAT environment and to get some anticipations on SQL runtime latencies. That I guess is a valid reason to have the SQL IDs in advance.

If you’re using Oracle 18c or above then you can use SET FEEDBACK ON SQL_ID, which means the SQL_ID for the currently executed SQL or PL/SQL statement is displayed after the results. This is very useful, and a huge time saver, when all you need is to know the SQL_ID. When feedback for SQL_ID is ON, then the value of the SQL_ID is assigned to a predefined variable _SQL_ID

And if you’re running below 18c then you can use dbms_sql_translator.sql_id package, it provides an interface for creating, configuring, and using SQL translation profiles, and you can use one of its function sql_id to get the SQLID in advance.

Let’s do the demo for both! Though I am running this on 12c, but still be able to use both options as connecting to the database via SQLcl (a SQL Dev CLI) version 21.4 and that has both the options available.

[oracle@ontadomain.fatdba bin]$ ./sql ontadbschema/xxxxxxxxx@testdb_ha

SQLcl: Release 21.4 Production on Tue Jan 04 02:58:04 2022
Copyright (c) 1982, 2022, Oracle.  All rights reserved.
Last Successful login time: Tue Jan 04 2022 02:58:06 +02:00

Connected to:
Oracle Database 12c Enterprise Edition Release 12.2.0.1.0 - 64bit Production

SQL>  select * from dixdroid.testtable;

               STATS_CORRNAME    STATS_CORRVALUE  STATS_CORRDESC
_____________________________ __________________ _________________
DEFAULT_LOCK_DURATI                           60 SECONDS
FIX_ALLOWED_LOCK_DURATI                      120 SECONDS
FIX_RETURNABLE_NUMBERS                       200
FIX_RETURNABLE_RANGES                         10
DEFAULT_RESERVATION_DURATI                    60 MINUTES

SQL>


-- Now trying the first approach which will work on < 18c versions.
SQL>
SQL> select dbms_sql_translator.sql_id('select * from dixdroid.testtable where STATS_CORRVALUE > 150') from dual;

1 row selected.

SQL_ID: 16jcpmjs087ct



-- Trying the second approach using SET FEEDBACK which works great if running >= 18c 
SQL> set feedback only sql_id
SQL> select * from dixdroid.testtable where STATS_CORRVALUE > 150;

1 row selected.

SQL_ID: 16jcpmjs087ct
SQL>
SQL>

Hope It Helped!
Prashant Dixit

Posted in Advanced, troubleshooting | Tagged: , , | 2 Comments »

 
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