Existence of tuples in relations and a multicolumn index. - Mailing list pgsql-general

If I have a relation and create a multicolumn index on all the
attributes,
would the index be bigger than the relation itself?
would it be more efficient to keep the relation ordered on all the
attribute if I have
a lot of additions?
I have relations that are only incremental in time and they are huge,
i.e. exponential
in the size of the rest of the database.
The problem arises when I have to check for existence of a tuple in
those type
of relations.

Regards,
    tzahi.

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