CouchDB API query with ?limit=0 returns one row - bug or feature?

Question

I use CouchDB 1.5.0 and noticed a strange thing:

When I query some API action, for example:

curl -X GET "http://localhost:5984/mydb/_changes?limit=1"

I get the same result with limit=1 and with limit=0 and with limit=-55. In all cases is a one row from the start of list.

Although, PostgreSQL returns:

• Zero rows when LIMIT 0
• Message ERROR: LIMIT must not be negative when LIMIT -55

My question is mainly concerned with the API design. I would like to know your opinions.

It's a flaw or maybe it's good/acceptable practice?

Answer 1

This is how the _changes api is designed. If you do not specify the type of feed i.e long-poll, continuous etc the default is to return a list of all the changes in a single results array.

If you want a row by row result of the changes in the database specify the type of feed in the url like so

curl -X GET "http://localhost:5984/mydb/_changes?feed=continuous"

Another point to note that in the _changes api using 0 has the same effect as using 1 in limit parameter.