Why a random string and not simply a sequence number?  The latter would have the advantage of definitely being unique (besides being trivial to implement), while a random string might (in theory) repeat, and thus not necessarily be "totally unique"... (which means you'd need to check against a hash holding already used IDs).  Also, for the reverse lookup a simple array would suffice.

In reply to Re^2: Generate unique ids of maximum length by almut
in thread Generate unique ids of maximum length by lima1

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