[Info-vax] CRTL and RMS vs SSIO

[Arne Vajhøj]

On 10/7/2021 2:30 PM, Stephen Hoffman wrote:
> PostgreSQL has been adding replication and clustering:
> https://www.postgresql.org/docs/9.5/different-replication-solutions.html
> 
> Whether an OpenVMS port of PostgreSQL can incorporate DLM calls is 
> fodder for future discussions, once the SSIO prerequisite becomes 
> available and a hypothetical future PostgreSQL port becomes stable. A 
> stable PostgreSQL will interest some folks, with adoptions depending on 
> both intrinsic interest and, um, potential extrinsic factors not yet in 
> evidence.

PostgreSQL clusters are active/passive.

All updates and typical all reads goes to the active node
and updates get replicated from the active node to the passive nodes.

I believe it is possible to have the passive nodes support
reading.

But with only the active node taking updates then there
is no need for DLM.

(VMS people may not even call such a config a cluster, but ...)

Arne