Adjust tile queries to allow for z16 metatiles

[nvkelso]

Specifically, we pack some stuff only into z17 and z18 tiles now. If we meta tile, then those need to be included in z16 (and perhaps marked that their min_zoom is only valid at z17, z18).

EG, in POIs:

             WHEN (aeroway_val IN ('gate')
                   OR amenity_val IN (
                 'atm', 'bicycle_rental', 'bicycle_parking', 'bus_stop',
                 'drinking_water', 'emergency_phone',
                 'parking', 'post_box', 'telephone', 'theatre',
                 'toilets')
                   OR highway_val IN ('bus_stop', 'traffic_signals')
                   OR historic_val IN ('memorial')
                   OR leisure_val IN ('playground', 'slipway')
                   OR man_made_val IN ('mast', 'water_tower')
                   OR office_val IN ('accountant', 'administrative', 'advertising_agency',
                'architect', 'association', 'company', 'consulting', 'educational_institution',
                'employment_agency', 'estate_agent', 'financial', 'foundation', 'government',
                'insurance', 'it', 'lawyer', 'newspaper', 'ngo', 'notary', 'physician',
                'political_party', 'religion', 'research', 'tax_advisor', 'telecommunication',
                'therapist', 'travel_agent', 'yes')
                   OR shop_val IN ('bakery', 'bicycle', 'books', 'butcher', 'car', 'car_repair',
                                 'clothes', 'computer', 'convenience',
                                 'doityourself', 'dry_cleaning', 'fashion', 'florist', 'gift',
                                 'greengrocer', 'hairdresser', 'jewelry', 'mobile_phone',
                                 'optician', 'pet')
                   OR tourism_val IN ('bed_and_breakfast', 'chalet', 'guest_house',
                                    'hostel', 'hotel', 'motel')
                   OR railway_val IN ('subway_entrance')) THEN 17
             WHEN (amenity_val IN ('bench', 'waste_basket')) THEN 18

[nvkelso]

Needs to be coordinated with scene file changes (to suppress these from display at zoom 16/17 as appropriate)

[rmarianski]

@nvkelso I discussed the implementation with @zerebubuth a little bit, and a good way forward would be to start including all pois in z16 tiles. For pois that don't have a min_zoom, we could set that to z18, or maybe flag that some other way?

[zerebubuth]

All POIs have a mz_poi_min_zoom, don't they? Otherwise,

  WHERE                                                                                              
    {{ bounds|bbox_filter('way') }}                                                                  
    AND mz_poi_min_zoom <= {{ zoom }}                                                                

The second part of the query would never be true?

[rmarianski]

Ah, never mind, I misunderstood earlier. If we just query for all pois that have a min zoom starting at z16, we'll get the behavior that we want.

[nvkelso]

Should we export the min_zoom property on all the POIs now, or only on the z17 and z18 features?

[rmarianski]

Related prs:

• Query updates to metatile at z16 #539
• Metatile at z16 tilequeue#73
• Metatile at z16 tileserver#17

[rmarianski]

I exported the min_zoom property on all POIs in the vector-datasource pr.

[rmarianski]

We might want to consider adding min_zoom to the boundaries layer too, to handle moving the barrier=fence and boundary=fence to z16.

[nvkelso]

LGTM, let's merge this in and test on dev.

Regarding adding min_zoom to the boundaries layer – let's file a new issue for that for future consideration. It's related to this work, but involves a bunch of other decisions that can be separated.

[rmarianski]

When deploying this change, we'll need to run a script that takes all toi at z>16, and ensures that the corresponding tile at z16 is added.

Should I make a python script for this and stick it in the migrations directory?

[zerebubuth]

Yup, sounds good.

[nvkelso]

@rmarianski: Do we need to prune any z17 and z18 tiles from Tiles of Interest list to support this z16 meta-tiling change, or was that already accomplished in our earlier pruning? I think it was, just double checking.

[rmarianski]

We shouldn't have do to worry about anything wrt pruning specifically for this change. The earlier pruning would have removed anything in this range with just 0 or 1 view.

[nvkelso]

I've tested on TopoJSON, GeoJSON, and MVT formats and all looks good.