- Available since:
- Time complexity:
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Returns the number of entries inside a stream. If the specified key does not
exist the command returns zero, as if the stream was empty.
However note that unlike other Redis types, zero-length streams are
possible, so you should call
EXISTS in order to check if
a key exists or not.
Streams are not auto-deleted once they have no entries inside (for instance
XDEL call), because the stream may have consumer groups
associated with it.