pg_plan_guarantee VS pg_ivm

For 4) I've heard there's this available https://github.com/DrPostgres/pg_plan_guarantee

Shameless plug(s). To address both the problems you described, I have developed the following Postgres extensions.

Index Adviser can be used to automatically analyze your workload, and it will suggest the indexes that might help your queries perform better.

Postgres Plan Guarantee (under development) helps you generate+freeze a plan, and ensure that the Query Optimizer will never pick a different plan for your query.

Postgres Index Advisor: https://github.com/DrPostgres/pg_adviser

Postgres Plan Guarantee: https://github.com/DrPostgres/pg_plan_guarantee

FTA, because I don't like Jeopardy questions in headlines:

“Incremental View Maintenance (IVM) provides a method for keeping materialized views current by calculating and applying only the incremental changes, as opposed to the complete recomputation of contents performed by the REFRESH MATERIALIZED VIEW command.”

Article shows using the pg_ivm Postgres extension available here: https://github.com/sraoss/pg_ivm

There is an extension that provides some limited incremental MVIEW refresh: https://github.com/sraoss/pg_ivm

There’s awesome work being done on incremental view maintenance in postgres:

https://github.com/sraoss/pg_ivm

It makes sense to perform managed denormalization - use a materialized view or automatically refresh a table or foreign server (via FDW) using common triggers (like pg_ivm does). And it's fine to add a TTL to it and use as a read store... update on user login and make a partial index just for that. And that's how you could get CQRS...