Is There Any Way ....

... to do the following:
  (1) Make a table memory-resident only ?
  (2) Set up user variables in memory that are persistent across all
sessions, for
      as long as the database is up and running ?
  (3) Assure that a disk-based table is always in memory (outside of keeping
it in
      memory buffers as a result of frequent activity which would prevent
LRU
      operations from taking it out) ?