Collection names can use any character in the ASCII set. Some valid
collection names are "", "...",
"my collection", and "*&#@".
User-defined collection names cannot contain the $ symbol. There are
certain system collections which use a $ in their names (e.g.,
local.oplog.$main), but it is a reserved character. If you attempt to
create and use a collection with a $ in the name, MongoDB will assert.
Descending direction for sorts and index creation.
Fields
db
The "parent" database for this collection.
w
The number of servers to replicate a change to before returning success.
Value is inherited from the parent database. The
MongoDB class has a more detailed description of
how w works.
wtimeout
The number of milliseconds to wait for $this->w
replications to take place. Value is inherited from the parent database.
The MongoDB class has a more detailed description
of how wtimeout works.