Paul Taylor <[email protected]> writes: > Knut Anders Hatlen wrote: >> Paul Taylor <[email protected]> writes: >> >> >>> HI, I use derby in embedded mode, I let the user specify a maxmium >>> size for the derby database files, my program monitors this and if it >>> goes over the size I use SQL to delete records that are no longer >>> necessary in the hope of shrinking the database files size, but it >>> doesn't, how can I force Derby to shrink back down ? >>> >> >> Hi Paul, >> >> The database files won't shrink unless you compress the tables. >> >> http://db.apache.org/derby/docs/10.6/ref/rrefaltertablecompress.html >> http://db.apache.org/derby/docs/10.6/ref/rrefproceduresinplacecompress.html >> >> Hope this helps, >> >> > Thanks guys that does help, the only problem is that it takes an > exclusive lock on the table and I wanted to run it in the background > as and when required when other tasks might be going ahead. But can > probaly work round this.
In the issue tracker there's a request for allowing more concurrent activity while compressing a table, but there hasn't been any work on it yet. https://issues.apache.org/jira/browse/DERBY-3974 -- Knut Anders
