Skip to content

Update source/release-notes/2.4.txt #436

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Nov 29, 2012
Merged
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
16 changes: 8 additions & 8 deletions source/release-notes/2.4.txt
Original file line number Diff line number Diff line change
Expand Up @@ -354,30 +354,30 @@ the :program:`mongo` shell that resembles the following:

This operation shards the ``active`` collection in the ``records``
database, using a hash of the ``a`` field as the shard
key. Consider the following properties when a hashed shard key:
key. Consider the following properties when using a hashed shard key:

- As with other kinds of shard key indexes, if your collection has
data, you must create the hashed index before sharding. If you
data, you must create the hashed index before sharding. If your
collection does not have data, sharding the collection will create
the appropriate index.

- The :program:`mongos` can route all equality queries to a specific
shards or set of shards using the hashed index; however, the
:program:`mongos` must route range queries to all shards.
- The :program:`mongos` will route all equality queries to a specific
shard or set of shards; however, the :program:`mongos` must route
range queries to all shards.

- When using a hashed shard key on a collection without data, MongoDB
automatically pre-splits the range of 64-bit hash values into
chunks. By default, the initial number of chunks is equal to twice
the number of shards at creation time. You can change the number of
chunks created, using the ``numInitialChunks`` option, as in the
following invocation of ``numInitialChunks``:
following invocation of ``shardCollection``:

.. code-block:: javascript

db.adminCommand( { shardCollection: "test.collection", key: { a: "hashed"}, numInitialChunks: 9001 } )
db.adminCommand( { shardCollection: "test.collection", key: { a: "hashed"}, numInitialChunks: 2001 } )

.. warning::

Avoid using hashed shard keys when the hashed field has floating
Avoid using hashed shard keys when the hashed field has non-integral floating
point values, see :ref:`hashed indexes <hashed-index-warning>` for
more information.