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From Stanley Bradbury <Stan.Bradb...@gmail.com>
Subject Re: DB File Size
Date Tue, 20 Jun 2006 18:35:43 GMT
LEE YAN SHEN, ITDO wrote:
>
> Hi,
>
> I have been doing stress test on the database doing lots of 
> insert/update/delete/query rapidly and found that one of the files is 
> growing rapidly although the number of records in the db remain more 
> or less constant during the test. In fact, it grew 100 over megabytes 
> after about 350,000 transactions. The only way to reduce the file size 
> was to do a compress table which made it reduce to only 2 MB.
>
> Is it the expected behaviour? From the documentation, derby should be 
> zero admin and be able to reuse space made available after a record is 
> deleted. Hence I do not expect the file size to grow constantly with 
> the same number of records.
>
> Can anyone advise please?
>
> Thanks.
>
>
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Hi -
What version of Derby are you using?  There are several enhancements 
filed to improve automated space reclamation for tables.  Some have been 
implemented and some have not.  If you are using a recent snapshot of 
Derby and still seeing this behavior then please check JIRA and see if 
your situation is described in one of the open enhancements.  If not 
please file an additional enhancement request describing the processing 
that is causing this growth.

Here are some of the issues that are still open:
The 'general' entry for ongoing work:
http://issues.apache.org/jira/browse/DERBY-512

Problem reclaiming space when an insert in aborted:
http://issues.apache.org/jira/browse/DERBY-691

=== Some resolved issues:
Reclamation of LOB columns
http://issues.apache.org/jira/browse/DERBY-670

In place compress ( SYSCS_UTIL.SYSCS_INPLACE_COMPRESS_TABLE):
http://issues.apache.org/jira/browse/DERBY-132
 >> NOTE: I do not think that the work has been done to have the system 
run this internally.

HTH






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