incubator-couchdb-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Jens Alfke <>
Subject Re: What am I doing wrong?
Date Fri, 20 Feb 2009 16:00:53 GMT

On Feb 20, 2009, at 6:03 AM, Pascal Borghino wrote:

> I am currently compacting it... even  if 'Compaction rewrites the  
> database file, removing outdated document revisions and deleted  
> documents'... no document should be outdate neither deleted...

In addition to the sparseness of the file, another reason for the size  
difference might be obsolete b-tree nodes. The file is append-only, so  
any time a b-tree changes, the old nodes remain in the file. If you've  
done a large number of individual insertions, that space might be  
significant. (Probably not gigabytes, though.) wrote:

> I find the actual
> consumed space is far, far less that 'ls' shows. CouchDB .couch files
> are very sparse, large gaps of unwritten data, ostensibly to keep
> btree and document items separate, but these 'holes' vanish after
> compaction, even if you have zero updates and deletes.

Hm. But not all filesystems support sparse files. HFS+, the Mac OS  
filesystem, doesn't. (Does NTFS?) Is there an option to suppress the  

View raw message