Requested array size exceeds VM limit

[Lucky]

Hi:
    I have a table with 20000000 records, 6 fields.

    When I use "select fid from userInfo " ,It got a error,like this:
Exception in thread "H2 Console thread" java.lang.OutOfMemoryError: Requested 
array size exceeds VM limit
      
     How to increase the heap?


     Thanks


    Lucky