pg_rerun_handlers_batched.js

var EventsEmitter = require('events').EventEmitter;

pg.connect(..., function(err, client, done) {
  var pageSize = 50;

  var emitter = new EventsEmitter();
  emitter.on('next', function(offset) {
    callHandlersPaginated(offset);
  });
  emitter.on('end', function() {
    done();
  });
  emitter.emit('next', /* initial offset */ 0);

  function callHandlersPaginated(offset) {
    var rowsProcessed = 0;
    client.query("select payload from events limit " + pageSize + " offset " + offset + " order by id");
    client.on('row', function(row, result) {
      // do stuff
      rowsProcessed++;
    });
    client.on('end', function(result) {
      // do stuff
      if (rowsProcessed >= pageSize) {
        emitter.emit('next', offset + pageSize);
      } else {
        emitter.emit('end');
      }
    });
  }
});