Renaming a Mongo Collection in PHP

Question

PHP's Mongo driver lacks a renameCommand function. There is reference to do this through the admin database. But it seems more recent versions of the Mongo driver don't let you just "use" the admin database if do don't have login privileges on that database. So this method no longer works. I've also read this doesn't work in sharded environments although this isn't a concern for me currently.

The other suggestion people seem to have is to iterate through the "from" collection and insert into the "to" collection. With the proper WriteConcern (fire and forget) this could be fairly fast. But it still means pulling down each record over the network into the PHP process and then uploading it back over the network back into the database.

I ideally want a way to do it all server-side. Sort of like an INSERT INTO ... SELECT ... in SQL. This way it is fast, network efficient and a low load on PHP.

Answer 1

I have just tested this, it works as designed ( http://docs.mongodb.org/manual/reference/command/renameCollection/ ):

$mongo->admin->command(array('renameCollection'=>'ns.user','to'=>'ns.e'));

That is how you rename an unsharded collection. One problem with MR is that it will change the shape of the output from the original collection. As such it is not very good at copying a collection. You would be better off copying it manually if your collection is sharded.

As an added note I upgraded to 1.4.2 (which for some reason comes out from the pecl channel into phpinfo() as 1.4.3dev :S) and it still works.