Firebird Database Keeps getting larger

views:

128

answers:

+1 Q:

Firebird Database Keeps getting larger

This one is interesting to me - despite the almost inane title. I have used Firebird for a long time, but not until recently noticed an interesting behavior.

I am using embedded firebird 1.5, and noticed that if I stuff the database full of blobs (lets say 10mb worth), the size of the database increases. I can then delete all the fields in the database, and the file size of the DB remains at its expanded size. Currently it is at 20mb and is completely empty.

I know that firebird has this built into its architecture (for quick indexing, speed issues etc), but I always thought it would decrease back down to its original ~2mb default.

Does anyone have any suggestions to 'deflate' the file size? The reason being is that this is a space conscious issue. If I had tons of space to work with, I wouldn't care. However that is not the case, and I need things to be as optimal as possible

Thanks!

+3 A:

The only way to free unused space in a firebird database is to do a backup then an immediate restore of that backup (Reference: Firebird FAQ).

Here is a good technical explanation of why this is so.

Note that Firebird will reuse the currently unused space - ie. if you put another 10MB of blobs in now, the database should not grow to 30MB.

Blorgbeard 2010-01-11 23:05:42

thanks for the answer - but what if the size of the database is due to use. Such as storing values in it, or blobs. A user uses the db for a while, and I would like it to be resized back down to its 2mb default (with all of info retained) if it doesn't need to be 20mb. Does that make sense? Maybe I am not following your logic?

Liam 2010-01-11 23:13:30

Updated my answer. Basically, there's no way apart from backup/restore. You could script this as a nightly/weekly task maybe?

Blorgbeard 2010-01-11 23:19:57

Thanks! I have read that page /minus/ the bottom part that mentions the backup/restore. Makes sense though, with how complicated the pointers are within the paging system. Thanks for taking the time and effort to post, and point me to the backup/restore part of the article.

Liam 2010-01-11 23:34:33

Ryan J. Mills 2010-01-18 15:11:57

ansaurus

tags:

views:

answers:

Firebird Database Keeps getting larger

related questions