Godeps/_workspace/src/gopkg.in/mgo.v2/session.go
func (q *Query) Prefetch(p float64) *Query {
	q.m.Lock()
	q.prefetch = p
	q.m.Unlock()
	return q
}
func (q *Query) Prefetch(p float64) *Query {
	q.m.Lock()
	q.prefetch = p
	q.m.Unlock()
	return q
}
func ( q * Query ) Prefetch ( p float64 ) * Query { q . m . Lock ( ) q . prefetch = p q . m . Unlock ( ) return q }
// Prefetch sets the point at which the next batch of results will be requested.
// When there are p*batch_size remaining documents cached in an Iter, the next
// batch will be requested in background. For instance, when using this:
//
//     query.Batch(200).Prefetch(0.25)
//
// and there are only 50 documents cached in the Iter to be processed, the
// next batch of 200 will be requested. It's possible to change this setting on
// a per-session basis as well, using the SetPrefetch method of Session.
//
// The default prefetch value is 0.25.
Prefetch sets the point at which the next batch of results will be requested . When there are p * batch_size remaining documents cached in an Iter the next batch will be requested in background . For instance when using this : query . Batch ( 200 ) . Prefetch ( 0 . 25 ) and there are only 50 documents cached in the Iter to be processed the next batch of 200 will be requested . It s possible to change this setting on a per - session basis as well using the SetPrefetch method of Session . The default prefetch value is 0 . 25 .