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
