> My system is in java and it has to save every day several diagnostic data on a log table.
> If you confirm that when I delete records, firebird reuses that space for next record adding,
> I can solve my problem deleting automatically the table for old logs.
> I can't use a bigger disk because it's an embedded system, and also with a bigger disk after
> some time I will reach the size limit continuing to add record.

Typically, if you take proper care of transactions, then the database file grows quite a bit at first, but after a while it stops growing and remain fairly stable. Firebird do reuse space, though after you delete a record, it may still be visible to other transactions and its space will not be made available for reuse until all transactions that can see it are committed or rolled back.

If you don't take proper care of transactions, then the database file might continue to grow indefinitely and you may run into trouble.

5 Gb is a considerable amount of data. Of course, it depends on what kind of data you're storing, huge blobs may consume a lot of space. Our main database contains two tables with about 1 million records each and one table with about 3 million records, and I think the size of the database might be 1-2 Gb.

HTH,
Set