[OSM-dev] Where to document recommendations for PostgreSQL regarding rendering

[Stephan Knauss]

Hello fellow developers,

where would be a good location to document settings to tune on 
PostgreSQL when setting up a rendering database?

There is a section within osm2pgsql, but maintainers hint that this 
might not be such a good location for settings potentially relevant for 
rendering.

https://github.com/openstreetmap/osm2pgsql-website/pull/12

In the wiki I found a page about PostgreSQL tuning, but this hints 
towards storing OSM data as per API access:

https://wiki.openstreetmap.org/wiki/PostgreSQL


I have not found any mentioning of database settings in 
openstreetmap-carto. Could that be a location to store such details?

https://github.com/gravitystorm/openstreetmap-carto/blob/master/INSTALL.md


I am thinking of content similar to what is within the osm2pgsql manual, 
probably starting with a copy and focusing on aspects of map rendering.

Especially the memory leak with PostgreSQL 12+ and using jit while 
rendering and the additional load impact of parallel workers without 
benefit seems worth to document. These are default settings of 
PostgreSQL and need adjustment.

Stephan