On Jul 7, 2008, at 2:56 PM, Jan Lehnardt wrote:
On Jul 7, 2008, at 20:38, Brad King wrote:
Maybe I don't understand compaction, but based on what I've read this
is meant to get rid of old doc versions, and essentially any
fragmentation that has occurred. What I'm seeing is for a brand new
database, I create approximately 300K documents and the size is
2.2GB.
I then run a compact from Futon, and size drops to 414MB. Since this
is a new database, which should only have one version of each
document, why the dramatic size change?
CouchDB trades disk space for read and write-speed as well. Not only
for consistency and having old revisions around. When you bulk insert
all docs, or a bunch of docs at a time, you see less usage than when
you do single inserts.
Correct. The wasted disk space are small bits of the internal indexes,
each time you update the database there will be old index data taking
up space. The amount of space wasted is a function (O(log n)) of the
total number of documents in the database, regardless if its one
document being saved, or 1000. Using bulk insert helps reduce the
wasted space. And compaction will eliminate it completely.
-Damien
Cheers
Jan
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