Portal | Manuals | References | Downloads | Info | Programs | JCLs | Master the Mainframes
IBM Mainframe Computers Forums Index
 
Register
 
IBM Mainframe Computers Forums Index Mainframe: Search IBM Mainframe Forum: FAQ Memberlist Usergroups Profile Log in to check your private messages Log in
 

 

Explain Utility

 
Post new topic   Reply to topic    IBMMAINFRAMES.com Support Forums -> DB2
View previous topic :: :: View next topic  
Author Message
Prabha
Warnings : 2

New User


Joined: 05 Dec 2005
Posts: 79

PostPosted: Fri Jul 09, 2010 2:43 pm    Post subject: Explain Utility
Reply with quote

Hi,

could you pleae let me know the usage of EXPLAIN utility and where we are handling?

Regards,
Prabha
Back to top
View user's profile Send private message

dbzTHEdinosauer

Global Moderator


Joined: 20 Oct 2006
Posts: 6968
Location: porcelain throne

PostPosted: Fri Jul 09, 2010 2:52 pm    Post subject:
Reply with quote

5.58 EXPLAIN SQL REFERENCE

6.4 Chapter 6-4. Using EXPLAIN to improve SQL performance SQL Appl Programmers guide

also, talk to your db2 support to determine what facilities already exist.
it may be that your site has VISUAL Explain.
Back to top
View user's profile Send private message
LearningDb2

New User


Joined: 19 Jun 2009
Posts: 40
Location: India

PostPosted: Fri Jul 09, 2010 5:31 pm    Post subject:
Reply with quote

Hi Prabha,

We use Explain to collect the information abt the access path used by the optimizer for the statement which is explainable.
Suppose you have a stored procedure having hundred's of SQL statements.Then u can use Explain for the sql's whose access path u want to see.Eg:- whether the predicates that u have specified in the select clause are using proper indexes or not.

We assign a query number through which we identify that statement in user created PLAN_TABLE.

Eg-: exlpain all set query number = nn for select.......(explainable statement)

All the informations derived by the Explain are stored in PLAN_TABLE.
Usually GroupID.PLAN_TABLE.

For the description of the columns of Plan_table you can hv a look at SQL reference(Statements-Explain).

Hope this Helps.

Thanks
Back to top
View user's profile Send private message
View previous topic :: :: View next topic  
Post new topic   Reply to topic    IBMMAINFRAMES.com Support Forums -> DB2 All times are GMT + 6 Hours
Page 1 of 1

 

Search our Forum:

Similar Topics
Topic Author Forum Replies Posted
No new posts How to Use DebugTool CodeCoverage Uti... neo4u IBM Tools 0 Thu Jun 22, 2017 6:38 pm
No new posts Search utility(3.14) using JCl and Cobol RKS3 COBOL Programming 12 Sat Jun 10, 2017 10:24 pm
No new posts DB2 - TERMINATE utility vasanthz DB2 5 Mon May 15, 2017 11:49 pm
No new posts HLIST Utility In Batch Virendra Shambharkar TSO/ISPF 4 Fri Apr 07, 2017 3:38 pm
No new posts TSO or command line utility to genera... kishpra JCL & VSAM 3 Thu Mar 09, 2017 1:11 am


Facebook
Back to Top
 
Mainframe Wiki | Forum Rules | Bookmarks | Subscriptions | FAQ | Tutorials | Contact Us