(Visual) Explain on z/OS

[juliane26]

Being new on z/OS for some time I do have some problems with Explain.

I tried the Visual Explain for z/OS, but since we use Version 7 database I can't even see the join predicates or any cost estimation.
I am not sure this is related to that we use V7 and the product has been designed for V8 database.
Since already in V7 documentation I find that I should see much more I tried to get an older version, but this is unfortunately not available for download anymore.

Second: Does anybody have a real good paper or so on the explain tables ?

Thank you !

Juliane

 

[MarcLodge]

Juliane,

Chapter 33 of the Admin Guide gives a thorough and in depth write up of Explain and how to estimate a statement's cost using DSN_STATEMNT_TABLE. You can find the guide here:

http://publib.boulder.ibm.com/cgi-bin/bookmgr/download/dsnagh11.pdf

but be warned that it's over 1200 pages to takes a while to download. In the guide it says that Visual Explain is available on a separate CD. Has anybody at your site got access to it?

Marc

 

[MarcLodge]

Juliane,

Just found this link:

http://wwwdb.inf.tu-dresden.de/files/teaching/ibmcert/701/db2cert7014-a4.pdf

which seems very informative.

Marc

 

[juliane26]

Thanks, Marc.

Your second document unfortunately is about LUW, I am talking about zOS, unfortunately there it is somewhat different.

I do have the admin guide, but I hoped for something a little more handy.

Looks like I have to fight through it then ...

What is also irritating me is that the Visual Explain (zOS) always talks about SEMIJOIN (which is correct and nice to have), but unfortunately this is not even described in the DB2 docs.


Juliane