[postgis-devel] Outdated PostGIS Help section regarding CLUSTER?

[Marco Boeringa]

Hi,

I noticed the PostGIS documentation mentions that CLUSTER cannot be run 
against GiST type index unless the column is set to NOT NULL. This seems 
outdated information, at least, I have never had issues with running 
CLUSTER in any recent (> 12) version of PostgreSQL, even though the 
spatial columns being clustered on, are not set to NOT NULL.

The example also seems to use outdated syntax compared to current 
PostgreSQL docs, that suggest 'USING' instead of 'ON' type syntax.

Lastly, I did once try to use BRIN as input for CLUSTER, which failed 
because BRIN is AFAIK not suitable as input for CLUSTER operations due 
to the technical implementation of BRIN. Maybe it would be good to 
mention this restriction instead in the docs.

https://postgis.net/docs/manual-3.3/performance_tips.html#database_clustering

https://www.postgresql.org/docs/current/sql-cluster.html

Marco