Subject RE: [firebird-support] Gbaked and restored database larger than the original?
Author Svein Erling Tysvær
Take a look here:

I'd add that restore also has a -use_all_space option. If you don't specify this, then pages are filled to approximately 80% (80% is preferable over 100% unless it is a read-only database). See or for more information.


-----Original Message-----
From: []
Sent: 8. juli 2015 11:48
Subject: [firebird-support] Gbaked and restored database larger than the original?


Just for my cursiosity and for a better understanding of Firebird: what can be a possible reason for a gbaked and restored (to a different file) database being _larger_ than the original one?
I've got a db of size 104521728 bytes. I do gbak -B -T database.fdb database.gbk, then gbak -C database.gbk newdatabase.fdb. The size of newdatabase.fdb is 104751104 (~ 200kB more).
I'm the only one messing with these databases, the platform is Linux x64, Firebird 2.5.2, all operations performed on the same machine, in the same file system. Before the backup-restore, a quite large chunk of metadata was added/altered in the original database (procedures, fields), which is the only clue I can think of at the moment (adding a default value to a field which had none?).
It's quite obvious why a restored database might be smaller than the original one (no garbage), but the other way around is a bit puzzling.
Both databases seem to work fine, so I'm in no trouble, but my ignorance in this matter bothers me nonetheless ;) I'd be grateful for any plausible explanations.

thanks in advance and best regards

Posted by: Tomasz Tyrakowski <t.tyrakowski@...>


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