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From Knut Anders Hatlen <Knut.Hat...@Sun.COM>
Subject Re: [jira] Updated: (DERBY-1107) For existing databases JDBC metadata queries do not get updated properly between maintenance versions.
Date Mon, 03 Apr 2006 14:48:02 GMT
Satheesh Bandaram <bandaram@gmail.com> writes:

> On 3/30/06, Knut Anders Hatlen <Knut.Hatlen@sun.com> wrote:
>> Satheesh Bandaram <satheesh@Sourcery.Org> writes:
>> I don't think there has been any metadata changes between maintenance
>> releases, and I suppose bug fixes should be the only changes between
>> maintenance releases. And I think it is more a downgrade issue than an
>> upgrade issue. I mean, for upgrade it's no problem if we don't add
>> upgrade code until a metadata change is made. The problem with this
>> approach is that we will still use the new query after a downgrade. As
>> long as the new query doesn't use new functions, new tables or new
>> syntax (not likely that we will add such things in a maintenance
>> release, I guess), the only consequence is that the bug is fixed even
>> after we downgrade.
> This seems like a good problem to have?

Yes, as long as we actually fix a bug and don't introduce a new
one. But we don't write bugs, do we? :) Adding a version number to the
query name could help us out of that situation.

>> Is performance a big issue? This will happen once per version
>> change. I agree that it could be solved when the need arises. See my
>> comments above.
> Performance could be a small issue for the first time following version
> change. Not sure how long recompiling all system SPSes take, but could be
> several seconds?

On my computer (AMD 3200+) it takes less than one second to drop and
recompile all SPSs (SYS and SYSIBM).

> If we are proposing recompiling between maintenance
> releases only, it may be ok... but this cost could be noticed for
> point-release changes as ODD.
> Looks like we agree this issue could be solved when the real need arises...

I'm fine with leaving the current behaviour when moving between
maintenance or point releases as it is. There still is a problem with
upgrade from 10.1 to 10.2, though. I have logged it as DERBY-1176 and
will upload a patch soon.

> I noticed Rick included this issue as one of the reasons for codefreeze
> delay. Rick, do you think this issue is more serious?
> While use of SPS for metadata has some serious advantages, it does cause
> complications too, I think. Necessary evil?

As long as we are aware of the complications, I think we can live with
them. Necessary evil? Sure, but I sometimes feel "pure evil" is more
accurate... ;)

Knut Anders

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