Migrating IBM Cloudscape to Version 10 - Issue

[Prathip Asaithambi <pr...@sasken.com>]

Hi,

   I have a application using Cloudscape database(version5.6).The Cloudscape Database size is 73.1 Giga bytes.After migrating the database from Cloudscape to derby(Cloudscape10.0) i have noticed the following

 1. The migrate derby Database size is reduced to 50.1 Giga bytes(which was 73.1GB with cloudscape)
 2. My Application become dead slow at the DB interaction layer

I have used IBM's migratetoderby.jar for my migration. Could anyone help me out what went wrong during migration

1. Why the Database size was reduced ?
2. Whether there is any upper limits during migration process?
3. Why Application get slowdown during Database interaction layer?which was good before migration

Please help me out by providing you inputs

Thanks & Regads,
A.Prathip


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Re: Migrating IBM Cloudscape to Version 10 - Issue

[Kathey Marsden <km...@sbcglobal.net>]

Bryan Pendleton wrote:
>
> I agree with Kristian; it sounds like you may have lost some indexes.
>
> Accidentally losing some important indexes during the migration would
> make your database smaller and slower.
>
> Perhaps run 'dblook' against the new database, and verify the physical
> schema against the physical schema of the old database (was there a 
> version
> of dblook for Cloudscape? probably. So maybe you can run dblook against
> both and diff the output.)
>
As I recall the tool will stop and fail to continue if it encounters a 
compatibility issue that it cannot resolve, but I think it spits out an 
error before stopping.   It's been a long time so I don't remember all 
the details.

Also,  after converting I suggest you upgrade to 10.5 to take advantage 
of performance and other fixes and get onto an official Apache release.

Thanks

Kathey

Re: Migrating IBM Cloudscape to Version 10 - Issue

[Bryan Pendleton <bp...@amberpoint.com>]

>  1. The migrate derby Database size is reduced to 50.1 Giga bytes(which 
> was 73.1GB with cloudscape) 
>  2. My Application become dead slow at the DB interaction layer

I agree with Kristian; it sounds like you may have lost some indexes.

Accidentally losing some important indexes during the migration would
make your database smaller and slower.

Perhaps run 'dblook' against the new database, and verify the physical
schema against the physical schema of the old database (was there a version
of dblook for Cloudscape? probably. So maybe you can run dblook against
both and diff the output.)

thanks,

bryan

Re: Migrating IBM Cloudscape to Version 10 - Issue

[Kristian Waagan <Kr...@Sun.COM>]

Prathip Asaithambi wrote:
>  
> Hi,
>  
>    I have a application using Cloudscape database(version5.6).The 
> Cloudscape Database size is 73.1 Giga bytes.After migrating the 
> database from Cloudscape to derby(Cloudscape10.0) i have noticed the 
> following
>  
>  1. The migrate derby Database size is reduced to 50.1 Giga 
> bytes(which was 73.1GB with cloudscape) 
>  2. My Application become dead slow at the DB interaction layer
>
Hello Prathip,

I have no experience migrating from Cloudscape to Derby, but a few 
questions pop up in my mind:
 - Has the size been reduced because the migrated tables have been 
compressed / recreated?
 - Have you verified that all the previously existing indexes are in 
place in the new db?
 - When migrating, where the indexes created before or after the tables 
were populated?

Regarding the performance drop you have seen, it's hard to say what's 
going on with the current information. Two suspects are missing indexes 
or outdated index statistics. More information about what kind of 
queries / operations have become slow may also be of help.

Can you also tell us which version of Derby and Java you are using?


Regards,
-- 
Kristian

> I have used IBM's migratetoderby.jar for my migration. Could anyone 
> help me out what went wrong during migration
>  
> 1. Why the Database size was reduced ?
> 2. Whether there is any upper limits during migration process?
> 3. Why Application get slowdown during Database interaction 
> layer?which was good before migration
>  
> Please help me out by providing you inputs
>  
> Thanks & Regads,
> A.Prathip
>  
>  
> SASKEN BUSINESS DISCLAIMER
> -------------------------
> This message may contain confidential, proprietary or legally privileged information. In 
> case you are not the original intended Recipient of the message, you must not, directly or 
> indirectly, use, Disclose, distribute, print, or copy any part of this message and you are 
> requested to delete it and inform the sender. Any views expressed in this message are 
> those of the individual sender unless otherwise stated. Nothing contained in this message 
> shall be construed as an offer or acceptance of any offer by Sasken Communication 
> Technologies Limited ("Sasken") unless sent with that express intent and with due 
> authority of Sasken. Sasken has taken enough precautions to prevent the spread of 
> viruses. However the company accepts no liability for any damage caused by any virus 
> transmitted by this email
>