>>>>> "MM" == Mike Matrigali <[EMAIL PROTECTED]> writes:
MM> Note that derby does automatically reclaim space from deletes
MM> for subsequent inserts, but the granularity currently is at
MM> a page level. So deleting every 3rd or 5th row is the worst
MM> case behavior. The page level decision was a tradeoff as
MM> reclaiming the space is time consuming so did not want to
MM> schedule to work on a row by row basis. Currently we schedule
MM> the work when all the rows on a page are marked deleted.
It seems like you are mixing two things here:
1. Reclaiming space for subsequent inserts in the same table, and
2. Reclaiming space to the file system (which can be used for
inserts into other tables).
I do not understand why reclaiming of space for 1. should be time
consuming. You can have a list of pages that have lot of free space,
each time you delete a record so that the amount of free space is
above a certain threshold, the page is added to this list.
For 2., it does not seem to happen automatically even for empty pages?
I have today deleted all records of a table with a 440MB file. The
size of the file has not changed.
--
Øystein
