Re: iSeries SQL and identity columns

[terry_bullard@xxxxxxxxxxxx]

Thanks Alan - So if the system is generating it - would I be correct in 
saying that there is an sql insert statement that was run  and the system 
needs to generate a unique key value for this identity column so DB2 takes 
over to get the highest value so it can then insert the new record?

I guess the other way of asking is this normal activity?  I.e. - if I had 
NO tables that where created with an identity key column - will DB2 still 
perform this type of check before it does an insert and would I still see 
these same types of sql statements being generated.  I'm really trying to 
determine if I need to chase this from a possible performance issue 
standpoint.

Thanks in advance,



Terry Bullard – Applications Programmer Analyst


"Contains Confidential and/or Proprietary Information. 
May Not Be Copied or Disseminated Without Express Consent of The Goodyear 
Tire & Rubber Company."



From:   Alan Campin <alan0307d@xxxxxxxxx>
To:     "RPG programming on the IBM i / System i" <rpg400-l@xxxxxxxxxxxx>
Date:   02/01/2011 01:41 PM
Subject:        Re: iSeries SQL and identity columns
Sent by:        rpg400-l-bounces@xxxxxxxxxxxx



Yes, it is system generated. It looks like the system is querying to
determine if the table has an identity key. You should be able to run the
same query but you could also use Ops Nav and generate SQL for all your
tables and just query for identity key.

On Tue, Feb 1, 2011 at 11:16 AM, <terry_bullard@xxxxxxxxxxxx> wrote:

> Hello All,
>
> Have been having some performance issues with web pages hitting our
> iSeries.  Set up SQL Exit program to be able to capture/log odbc sql
> statements.  Looking in my log file - the overwhelming log entries have
> the following sql statement.
>
> SELECT identity_generation FROM QSYS2/SYSCOLUMNS WHERE 
identity_generation
> is not null AND column_name = ? AND table_name = ? AND table_schema = ?
>
> I have never seen a statement use the identity_generation field.  From
> what I can tell from IBM's website - this is a col you can add when
> creating a sql table and is used to support a type of "auto increment" 
key
> value?
>
> So - a couple of questions?  Is there a way (perhaps with Ops Navigator)
> to find a list of all tables that have this identity_generation column 
so
> I can backtrack to see what web pages are being called?
>
> Also - is this a system generated statement?  I ask because the 
developers
> who have written most of our web pages are telling me they don't 
recognize
> this either???
>
> Know this is not much to go on but it's what I have at the time.  Any
> thoughts would be greatly appreciated.....
>
> Thanks
>
>
>
> Terry Bullard – Applications Programmer Analyst
>
>
> "Contains Confidential and/or Proprietary Information.
> May Not Be Copied or Disseminated Without Express Consent of The 
Goodyear
> Tire & Rubber Company."
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