openmaptiles/layers/park
Brian Sperlongano 0cff3449b5
Implement non-blocking refresh (#1308)
This PR implements non-blocking updates in the park layer.

The approach was to use the `REFRESH MATERIALIZED VIEW CONCURRENTLY` feature in postgres.  In order to achieve this, a unique index was added on the z4 dissolved park area table.  The `ST_Union` / `ST_Dump` sequence was changed to an explicit cluster DB scan (an equivalent operation) so that a unique osm ID could be generated from each dissolved polygon.

Below is a screen shot from Idaho, USA showing that the dissolved z4 still works as expected.

![image](https://user-images.githubusercontent.com/3254090/142341513-588045f0-7757-4acd-99e5-a50bbe6b0682.png)
2021-11-24 11:17:29 +01:00
..
README.md
etl_diagram.png
mapping.yaml
mapping_diagram.png
park.sql
park.yaml
update_park_polygon.sql Implement non-blocking refresh (#1308) 2021-11-24 11:17:29 +01:00

README.md

park

Docs

Read the layer documentation at http://openmaptiles.org/schema#park

Mapping Diagram

Mapping diagram for park

ETL diagram

ETL diagram for park