Can i delete this for one key only

Of course. Simply amend your algorithm to maintain a separate list (which could be a hash for easy/fast lookups) of deleted values. Never delete a value which is already in that list.

In reply to Re^2: Hash Multiple values for a key-Filtering unique values for a key in hash by hippo
in thread Hash Multiple values for a key-Filtering unique values for a key in hash by rahulme81

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