It's not the size of the dataset that is relevant but more that this dataset changes in realtime : price + availability. These requests go through GDSs that are

It's not the size of the dataset that is relevant but more that this dataset changes in realtime : price + availability. These requests go through GDSs that are relatively slow, that's why so called real-time search engines like kayak are fairly slow. What do you exactly mean by 7M flights? Keep in mind that most search requests involve a combination of flights (leg), outbound, inbound and sometime multiple stops...