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  #1 (permalink)  
Old 11-21-03, 05:05
wasowsky wasowsky is offline
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Location: Milan, Italy
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DB2 Index Advisor

Well folks,
strange things happen in my DB2 for Linux and Windows boxes.

I've created a simple SQL workload, made of 5 SQL statements, just to test the tool.
Well, the advisor doesn't recommend any index, it just goes blank.

The funny thing is that the equivalent command line tool, db2advis, works wery well;

this is the syntax I used:

db2advis -d MYDBNAME -w WKLNAME -o DDLFILE.TXT

The workload WKLNAME is the SAME I created via the GUI advisor !

So, it DOES recommend indexes, it says how much I will gain in performance percentage, then, last but not least, it create the DDL job containing the CREATE INDEX statements.

Very nice indeed.

So, in your opinion, what can be wrong with the GUI advisor ?

Thanks in advance. Bye.
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Old 11-23-03, 18:59
quigleyd quigleyd is offline
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Location: Delaware
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I use the index advisor alot, but as a DBA, I don't rely 100% on it. I have found times that I have thought of the index the way I want to create it but the advisor has said something else. I then found out through testing that my way showed a better performace improvement(and vice versa) . So I wouldn't rely 100% on it, its a tool and like all tools, its not going to be perfect, just like us humans.
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Old 11-24-03, 01:13
grofaty grofaty is offline
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Posts: 1,570
Hi wasowsky,

I think there is a problem if <enter>, <tab> or any other unusual character is used. Try do remove all that kind of characters and try again.

Hope this helps,
Grofaty
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Old 11-24-03, 03:44
sathyaram_s sathyaram_s is offline
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Join Date: Aug 2001
Location: UK
Posts: 4,534
quigleyd is right ... Index advisor doesn't always give the correct indexes,in particular, the performance imporvement projection ...

I normally test with the indexes i think is useful and also the indexes suggested by the advisor ... Whichever gives better performance, I take that one ....

Cheers
Sathyaram
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