Add total_stationed_gmax to stations

[Mygod]

Fixes #239.

Some more context for justifying the change: https://www.reddit.com/r/TheSilphRoad/comments/1gpavlj/some_observations_on_maxspot_wildspawns/

[Fabio1988]

To understand this, the information is already in stationed pokemon, but we want to have an additional column to prevent ugly JSON queries, right? :)

[Mygod]

Yes basically. (I would also guess that JSON queries are not as efficient.) Is there a better way to do this? 🤔

[jfberry]

Yes basically. (I would also guess that JSON queries are not as efficient.) Is there a better way to do this? 🤔

Probably depends on the context records are going to be retrieved. If it were to be used for filtering stations, for example, then this is probably the way. If it is used as an attribute for a station and the tool (eg ReactMap) has already pulled the entire station record then this is probably superfluous.

[Mygod]

Yes. I'm planning to use it for filtering. Do we also need an index for that column?

[jfberry]

Yes. I'm planning to use it for filtering. Do we also need an index for that column?

For reactmap, most often additional indexes don't help as the request will prefer to use the lat, lon index. You should test on large data sets using EXPLAIN ANALYZE but my guess would be that this would not be helpful.

[Mygod]

Okay. So we can merge this now? 😄

[jfberry]

Okay. So we can merge this now? 😄

Has there been any corroborating information this is useful? There's nothing to stop you building a branch version of ReactMap that uses this -- this is the normal form to experiment with two parallel branches to harden before merging something that is shown to fully work and be useful

[Mygod]

@jfberry WatWowMap/ReactMap#1074