On Wed, Aug 4, 2010 at 12:07 PM, Steven Prentice < [email protected]> wrote:
> > > ---------- Forwarded message ---------- > From: Paul Joseph Davis <[email protected]> > Date: Wed, Aug 4, 2010 at 11:58 AM > Subject: Re: VIEW Performance Testing Help > To: "[email protected]" <[email protected]> > > > > > > > On Aug 3, 2010, at 7:31 PM, Steven Prentice <[email protected]> > wrote: > > > Hey Couchinators! > > > > My friend and I are trying to test the impact that views have on the size > of > > the database and have a few questions... > > > > 1. if the value of a view is set to 'doc' does that mean that the leaves > of > > the view B-Tree are now documents or are they simply pointers to the > > document leaves in the database B-Tree? > > i.e would the summed memory of all of the values in the view be equal to > the > > size of the database (ignoreing revisions)? > > Whatever you emit as a value is stored in the btree. So if you emit an > entire document it is stored completely in that view. A way to avoid this is > to use the include_docs=true parameter but it has some read performance > trade offs because it's a lookup per view row. The best idea is to only emit > what's actually needed. > > > > 2. also we would like to know if the database size that is displayed in > > futon includes the size of the views? > > Unless I missed that commit, no, db size is the size of just the .couch > file. > > > 3. Oh also, Revisions...is a revision an entire document or does a > revision > > only track changes in a document? > > Neither. A revision is just the string-id pair (More precisely it's a node > in the revision tree, but it still has zero info on actual document > content). That's all that will remain on disk after a compaction. Because > we're tail append the previous entire documents remain on disk until > compaction. To illustrate, we've had discussions on removing access to old > revisions and renaming revision to something else that doesn't make people > think they'll always have access to old versions of a document. > > > Cheers > > Steve + Adam > > HTH, > Paul Davis > > How would we check how much space that just the views are taking up? cheers!
