Eﬀec%ve’SQL’Tuning’Using’’ Oracle’s’Real’Time’SQL…Symposiu… ·...

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Effec%ve SQL Tuning Using Oracle’s Real Time SQL Monitor Kasey Parker Enterprise Architect [email protected]

Managed Services

Cloud Services

Consul3ng Services

Licensing


Who is Centroid?

§  Centroid is a leading provider of Oracle Technology, Applica8ons and Infrastructure/Hos8ng solu8ons

§  Oracle Pla8num Partner •  Oracle’s 2015 Engineered Systems Partner of the Year for North America •  Selected to Oracle’s Top 25 Strategic Partner Program •  Top 5 Oracle Partner for Hardware/Storage

§  Established in 1997

§  Office loca8ons: Troy, MI (HQ); San Francisco, CA; Los Angeles, CA; Dallas, TX

§  200+ Consultants

§  “Clients for life” approach to customer rela8onships

§  Oracle Exadata Center of Excellence established in 2011 • Centroid Authored -‐ Oracle Exadata Recipes (Published Feb-‐2013)

QUICK FACTS


Agenda § Why Real-‐Time SQL Monitor (RSM)? § What is it? §  How do I access it? § What can I get from it and how do I interpret? § What’s new for 12c? §  Q&A


Too many different traces to get what

I’m looking for

I want a tracing tool I can use without going to a DBA

What’s a good way to trace parallel processes?

I want a simpler way to trace my SQL

How do I see trace information while my statement is running?

How do I interpret execution plans that are

100+ lines long?

How’s your SQL tuning going?

Is there an easy way to see if I got a

Smart Scan?


The Answer… Real-‐Time SQL Monitor


Real-‐Time SQL Monitor Overview •  Introduced in 11G

– Ac3ve Report Introduced in 11GR2 – New 12c wait and plan step informa3on available

•  Feature includes new views, hints, func3ons and reports

•  Most value available in the Ac3ve XML version of the SQL Monitor Report

•  My opinion: Best tool ever created by Oracle to tune and troubleshoot SQL on Oracle database


Real-‐Time SQL Monitor Basics •  Allows detailed monitoring of SQL Statements while they are execu3ng

•  No Performance Penalty –  Similar to AWR and ASH, informa3on efficiently captured by background processes

•  Statements consuming >5 seconds of DB 3me or executed in parallel monitored by default

Use /*+ MONITOR */ hint to force


Real-‐Time SQL Monitor Basics Informa3on Accessible from:

•  Associated V$ views –  V$SQL_MONITOR, V$SQL_PLAN_MONITOR

–  Join with other views like V$SQL, V$ACTIVE_SESSION_HISTORY and V$SESSION_LONGOPS

•  Befer way: SQL Monitor reports –  Accessible with DBMS_SQL_TUNE.REPORT_SQL_MONITOR

–  Text, HTML, Ac3ve

•  Best way: Ac%ve XML SQL Monitor report –  Available from OEM and DBMS_SQL_TUNE


Accessing SQL Monitor Using Enterprise Manager •  Access from the Performance home by clicking on

the SQL Monitoring link at the bofom of the page

•  Or in 12c there is now a direct link from the Performance Menu


Accessing SQL Monitor SQL Monitoring link opens Monitored SQL Execu3ons


Accessing SQL Monitor Clicking an execu3on opens the Ac3ve SQL Monitor


Accessing SQL Monitor Using DBMS_SQLTUNE package •  Generate using

DBMS_SQLTUNE.REPORT_SQL_MONITOR func3on

•  Requires many “DBA” type permissions including: –  ADMINISTER SQL MANAGEMENT OBJECT

–  ADMINISTER ANY SQL TUNING SET

–  ADVISOR

–  Select rights on many performance views: •  V$SQL*, V$ACTIVE_SESSION_HISTORY, V$SESSION_LONGOPS and

most DBA_HIST* views


Accessing SQL Monitor SET LONG 1000000 SET LONGCHUNKSIZE 1000000 SET LINESIZE 1000 SET PAGESIZE 0 SET TRIM ON SET TRIMSPOOL ON SET ECHO OFF SET FEEDBACK OFF SET HEADING OFF SET SHOW OFF SET VERIFY OFF SPOOL report_sql_monitor_acIve.htm SELECT DBMS_SQLTUNE.report_sql_monitor( sql_id => '1kf86hqsyvddb’, type => 'ACTIVE', report_level => 'ALL') AS report FROM dual; SPOOL OFF

Example:


Access by Developers If concerned about level of privileges, put a wrapper func3on, owned by a privileged user, around the DBMS_SQLTUNE.REPORT_SQL_MONITOR func3on. Then grant execute on the func3on to your developers.

CREATE OR REPLACE FUNCTION EXEC_REPORT_SQL_MONITOR( p_sql_id in varchar2

) RETURN clob IS v_report_clob clob; BEGIN v_report_clob := dbms_sqltune.report_sql_monitor(SQL_ID => p_sql_id); RETURN v_report_clob; END;


Access by Developers A developer can then generate the report using a script:

set long 1000000 set longchunksize 1000000 … column spoolfilename new_value splfile accept sql_id prompt 'Enter value for sql_id: ‘ select 'sqlmon_' || '&&sql_id' || '.html' as spoolfilename from dual ; spool &splfile SELECT EXEC_REPORT_SQL_MONITOR( p_sql_id => '&&sql_id', p_type => 'ACTIVE') AS monitor_report FROM dual; spool off undef sql_id undef spoolfilename undef splfile


Access by Developers How to find the SQL ID? Use V$SQL…

set lines 200 pages 60 set feedback off echo off set verify off set pagesize 999 variable sql_id varchar2(30) variable sql_text varchar2(80) set feedback on select /* NORESULT */ sql_id from gv$sql s where sql_text like '%&sql_txt%'

and sql_text not like '%NORESULT%' and sql_text not like 'BEGIN :sql_%’

order by 1 desc / undef sql_id undef sql_text


What’s in a SQL Monitor Report A wealth of informa3on including: •  Execu3on Plan •  Plan sta3s3cs

–  Es3mated vs. actual row counts – a key indicator for sta3s3c problems •  DB Time break down and wait sta3s3cs

–  Execu3on’s overall dura3on vs. DB 3me –  CPU and wait events for each execu3on step and the 3me spent on each

•  Bind Variable Values •  IO Sta3s3cs •  Memory sta3s3cs •  Temp space sta3s3cs •  Parallel ac3vity detail •  CPU, IO, Memory and Wait ac3vity mapped over the statement run 3me •  Exadata cell offload (smart scan) efficiency


DEMO


SQL Monitor Use Cases SQL Monitor can help with things like: •  Breaking down, understanding and quickly iden3fying problem

areas of large execu3on plans •  Op3mal use of indexes •  Par3ally parallelized SQL •  Verifying parallel DML/DDL •  Detec3ng skew between parallel processes •  Iden3fying network, applica3on or other latency outside of

database processing •  Cause of high temp usage •  Verifying Exadata Smart Scans and cell offload efficiency •  And many more!


SQL Monitor Use Case

Breaking down, understanding and quickly iden3fying problem areas of large execu3on plans


SQL Monitor Use Case Enabling Parallel DML


SQL Monitor Use Case Par3ally Parallelized SQL


SQL Monitor Use Case Verifying Exadata Smart Scans and Cell Offload Efficiency


WHAT’S NEW FOR SQL MONITOR IN 12C?


In-‐Memory Query in SQL Monitor


Real-‐Time DB Opera3on Monitor Expand SQL Monitor to defined Database Opera3ons •  Iden3fy and Execute a Database Opera3on by:

–  Iden3fy the database opera3on •  Opera3on Name •  Execu3on ID

–  Start and end the database opera3on •  DBMS_SQL_MONITOR.BEGIN_OPERATION •  DBMS_SQL_MONITOR.END_OPERATION.

SQL> VAR dbop_eid NUMBER; SQL> EXEC :dbop_eid := DBMS_SQL_MONITOR.BEGIN_OPERATION

('ORA.ETLLOAD.FINANCE', FORCED_TRACKING => 'Y') SQL> INSERT /*+ APPEND */ * INTO tab1 SELECT ...; SQL> INSERT /*+ APPEND */ * INTO tab2 SELECT ...; SQL> EXEC DBMS_SQL_MONITOR.END_OPERATION

('ORA.ETLLOAD.FINANCE’, :dbop_eid)


Runaway Query Logging Resource Manager can now log to SQL Monitor

–  Based on certain thresholds: •  Es3mated Execu3on Time •  Elapsed Time (new in 12c) •  CPU 3me •  IO requests or IO Bytes •  Logical IOs (new in 12c)

–  New columns in V$SQL_MONITOR •  RM_LAST_ACTION •  RM_LAST_ACTION_REASON •  RM_LAST_ACTION_TIME

–  Can also s3ll switch consumer group, Abort Call or Kill Session


Summary •  SQL Monitor may be the best tool ever created by Oracle to tune and troubleshoot SQL on Oracle databases

•  Use the Ac3ve SQL Monitor Report –  Access through OEM or DBMS_SQLTUNE

•  Contains a wealth of informa3on about the SQL Execu3on

•  Can help iden3fy and resolve most of the issues found with SQL Statements

•  New Features from 12c expand its capability


Ques3ons?

Date post:	27-Jul-2018
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