CouchDB view is extremely slow

Views are only updated the next time they are read. Upon reading, it processes all the documents that have been updated (created, updated, deleted) since the last time the view was read.

So even if you're view was defined before inserting the 3890000 documents, it will be processing the 3890000 documents for the view.

From http://wiki.apache.org/couchdb/Introduction_to_CouchDB_views

Note that by default views are not created and updated when a document is saved, but rather, when they are accessed. As a result, the first access might take some time depending on the size of your data while CouchDB creates the view. If preferable the views can also be updated when a document is saved using an external script that calls the views when updates have been made. An example can be found here: RegeneratingViewsOnUpdate

Also just came across this tip, which might be useful if you're running on Ubuntu:

http://nosql.mypopescu.com/post/1299848121/couchdb-and-ubuntu-configuration-trick-for

Don't emit the whole doc. It's unnecessary. You can instead run your query with include_docs=true, which will let you access the document via each row's doc attribute.

When you emit the whole doc you make the index as large or larger than your entire database. :)