PostgREST is a standalone web server that turns your PostgreSQL database directly into a RESTful API. The structural constraints and permissions in the database determine the API endpoints and operations.
For many years MySQL and PostgreSQL were competing databases, which addressed slightly different audiences. Here's why you always should go for PostgreSQL!
Slony-I is a "master to multiple slaves" replication system supporting cascading (e.g. - a node can feed another node which feeds another node...) and failover.
NB: as you probably know, you can list tables/indices/sequences/views from the command line with the \d{t|i|s|v} command, but here I want to show how to extract these informations using standard SQL queries.