Just wanted to add that if you have a map function that emits (tag, 1) for each
tag and then a reduce function that's just _count, you will have everything you
need for painting a tag cloud.
The view with group=true will list all tags exactly once, with their count.
CouchDB doesn't tell you how many rows are in the result so you'll have to
count them yourself.
So you load that entire view in memory and you can draw the tags with their
relative sizes.
Wout.
On Oct 12, 2010, at 15:09 , Anand Chitipothu wrote:
> Is it possible to count the number of unique values by writing a couchdb view?
>
> A typical example is to find the number of tags in a blog application.
>
> Consider the following 2 docs.
>
> {
> "_id": "posts/1",
> "title": "post 1",
> "tags": ["foo", "bar"]
> }
>
> {
> "_id": "posts/2",
> "title": "post 2",
> "tags": ["foo", "foobar"]
> }
>
> Is it possible to find that there are 3 tags?
>
> Anand
