Clique search is NP-complete and if you are expecting cliques with "hundreds of members, if not thousands" it's unlikely you can solve the general case with a generic algorithm in acceptable time.

You have only a chance if your huge graph has special properties - like symmetries - simplifying the task.

Update

See also https://en.wikipedia.org/wiki/Clique_problem

Cheers Rolf
(addicted to the Perl Programming Language :)
Wikisyntax for the Monastery FootballPerl is like chess, only without the dice

In reply to Re^5: Sub set where all are connected (updated) by LanX
in thread Sub set where all are connected by Sanjay

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