Indexing travel types with PageRank weights

[da115115]

When someone searches for common types and/or countries, there is first a full text matching process, retrieving a maximum number of POR, for instance currently 30. Out of that limited list, the one with the highest PageRank value is then returned. That works well for cities (e.g., "paris airport"), but not so well for countries and/or travel types (e.g., "france airport", "uk railway", or just "usa" or "airport").

So, when indexing on the country level and/or travel type, it would be good to weigh with the PageRank value of the POR.

[da115115]

The commits tracked by the [Weights] tag implement that requested feature:

• 8a1e69bc7322a44094ff83f1da59bc9e7cd45631
• 780321f6d303766dd74c5de95291c205777bc05b
• ab31e69963b84506e6f96da219031183584e12b4

The following requests now work as expected:

• paris, returning the city of Paris, France (PAR).
• texas, returning the city of Dallas, TX, US (DFW)
• paris texas, returning the city of Paris, TX, US (PRX)
• del, returning the city of Delhi, India (DEL)
• san, returning the city of San Diego, CA, US (SAN)
• los las san rio los, returning a nice round trip departing from Lagos (LOS) going through Las Vegas (LAS), San Diego (SAN) and Rio de Janeiro (RIO).

[da115115]

Reopened because of the note below.

For some reasons (probably because the PageRank-based indexing weights are not big enough), the following requests bring not so bad answers, but not exactly what would be expected:

• france, returning the airport of Orly, France (ORY), where as the airport of Charles de Gaulle, France (CDG) would have been expected.
• australia, returning the city of Perth, Australia (PER), where as the city of Sydney, Australia (SYD) would have been expected.

[da115115]

See also #3 (Airport/city codes should take the precedence over alternate names) and #4 (Standsted STN).