Question

Contrived example:

{
  productName: 'Lost Series 67 DVD',
  availableFrom: '19/May/2011',
  availableTo: '19/Sep/2011'
}

View storeFront/currentlyAvailableProducts basically checks if current datetime is within availableFrom – availableTo and emits the doc.

I would like to force a view to regenerate at 1am every night, i.e. process/map all docs.

At first I had a simple python script scheduled via crontab that touched each document hence causing a new revision and the view to update,however since couchdb is append only this wasnt very efficient – i.e. loads of unnecessary IO and disk space usage followed by compaction, very resource wasteful on all fronts.

Second solution was to push the view definition again via couchapp push however this meant the view was unavailable (or partially unavailable) for several minutes which was also unacceptable.

Is there any other solutions?

Answer 1

So your view is not being updated automatically I take it?

New and changed documents are not being added on the fly?

Oh I see, you’re cheating. You’re using “out of document” information (i.e. the current date) during view creation.

There’s no view renaming, but if you were desperate you could use url rewriting.

Simply create a design document “each day”: /db/_design/today05172011

Then use some url rewriting to change: GET /db/_design/today/_view/yourview

to: GET /db/_design/today051711/_view/yourview

Create the view at 11pm server time (tweak it so that “now” is “tomorrow”, or whatever).

Then add some more clean up code to later delete the older views.

This way your view builds each night as you like.

Obviously you’ll need to front Couch with some other web server/proxy to pull this off.

It’s elegant, and inelegant, at the same time.