postgresql_cursor (rubygems):   PostgreSQL Cursor is an extension to the ActiveRecord PostgreSQLAdapter for   very large result sets.  It provides a cursor open/fetch/close interface to   access data without loading all rows into memory, and instead loads the result   rows in 'chunks' (default of 1_000 rows), buffers them, and returns the rows   one at a time. 
Keywords: activerecord|batch|cursor|for-update|large-scale|postgresql|postgresql-cursor|ruby|ruby-gem