Question

How can I add an index in production code? I have found only the way to add it as a command and not embedded in a complete code:

If you want to add indexing to speed queries:

db.users.ensure_index(the_key)

So I tried to add it to a class:

class Registration(BaseHandler):
    def post(self):
        # do stuff to get user information using the self.get_argument()
        user={"all information":informations}
        self.db.users.insert(user, w=1)
        self.db.users.ensure_index(pseudo, commune)

But I get errors like this:

self.db.users.ensure_index(pseudo, commune)
      File "build\bdist.win-amd64\egg\pymongo\collection.py", line 829, in ensure_index
      return self.create_index(key_or_list, cache_for, **kwargs)
  File "build\bdist.win-amd64\egg\pymongo\collection.py", line 740, in create_index
    self.__name, name, cache_for)
  File "build\bdist.win-amd64\egg\pymongo\connection.py", line 330, in _cache_index
    expire = datetime.timedelta(seconds=cache_for) + now
TypeError: unsupported type for timedelta seconds component: unicode

And I guess it will be the same tip when using inserting a sub-document:

self.db.users.update({"email":email}, {"$push":{"produit_up":{"id":id, "namep":namep, "nombre":nombre}}})
self.db.users.ensure_index("product_up.namep") #????

Answer 1

got the answer:

No No, ensureIndex is the same as creating an index. It does nothing
special, maybe the name of the function is a little odd really and should
be called create_index instead.
Since Mongo has no pre-defined schema (NoSQL) it has to create indexes a
different way to SQL. The way proposed was through client side when the
user decides they need an index on a particular field. This is how
collections and what not are created, when they are used by the client.
This function was called ensureIndex().
So there is only one call needed to ensureIndex() within your app and it
should be a list of fields for that index as the first param and any extra
options (like sparse) for the second param.
There is no work needed by the administrator to keep this index intact,
well not once a month but if something fails in the cluster then yea, some
work will be needed by the admin to possibly remake the index.
I personally have a file of indexes I call everytime my app is loaded.
I hope this clears things up a little,

answer from Google groups