Subject How to estimate free space inside database file
Author Bryan Cole


I am trying to figure out the amount of free space within my database, so that I can detect when I'm nearing exhausting the disk space. I'm using firebird-v2.5.2.

I know that (total_pages * page_size) = size on disk. This doesn't tell me how many of those allocated pages are free. If I delete a large number of records, the file size remains the same but pages should be freed internally. It is this free space I need to measure. While gstat gives me the number of data pages for each table, this *doesn't* include BLOB pages (which are the bulk of my data). How can I count BLOB pages?