db-derby-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Kristian Waagan <Kristian.Waa...@Sun.COM>
Subject Re: backup size exploded
Date Mon, 29 Oct 2007 08:58:07 GMT
Fabian Merki wrote:
> hi all
>  
> i encountered a very strange problem.
> today the backup of a small db was 7.4 gb and it filled up my disk.
>  
> running "du -s" results in:
>  
> 105194  backup/2007-10-14 03-09-31/
> 105214  backup/2007-10-15 03-10-23/
> 105250  backup/2007-10-16 03-09-40/
> 105318  backup/2007-10-17 03-09-29/
> 202713  backup/2007-10-18 03-09-52/
> 370164  backup/2007-10-19 03-10-36/
> deleted the other backups in the meantime (space problems!)
> if there were that many rows/data in my db i would not write this mail.
> the strangest thing of all is that count(*) on one of the problematic 
> tables is 141'655 while this table has 571'211 pages while 
> estimspacesaving is 0 (numfreepages=0, numfilledpages=1).
> the row-layout is 2 x bigint + 2 x 255varchar - this is much less than 1 kb
> the pagesize is 4kb - more than one row should fit in one page
>  
> i run CALL SYSCS_UTIL.SYSCS_BACKUP_DATABASE(...) every day.
>  
> can anyone explain why the db started to grow so quickly in size? why 
> would the numallocpages be more than count(*) - i never delete rows in 
> this table!?!?

Hello Fabian,

I don't have an answer to your question, but I have a few questions for 
you :)

1. How is the data inserted into your database?
2. Do you have multiple connections inserting the data cuncurrently?
3. Have you tried compressing the table(s)?
4. Have you specified any tuning-properties for the storage-layer/-engine?


These are just a few questions to help us understand what's going on. 
Hopefully someone will be able to give you a solution to your problem.
It would be interesting to see what happens if you try to compress the 
tables.

>  
> i'm using db-derby-10.2.2.0-bin and jdk1.5.0_09 (ok, i should update 
> sometimes...)

Which operating system are you using?


regards,
-- 
Kristian


>  
> thanks for any help
> fabian


Mime
View raw message