PG Sharding

Hi Everyone.

We are looking at a rather large fin-tech installation. But as scalability
requirements are high we look at sharding of-course.

I have looked at many sources for Postgresql sharding, but we are a little
confused as to shared with schema or databases or both.

So far our understanding:

*SCHEMA.*

PROS:
- seems native to PG
- backup seems easier
- connection pooling seems easier, as you can use same connection between
shard.

CONS:
- schema changes seems litlle more complicated
- heard of backup and maintenance problems
- also some caching problems.

*DATABASE:*

PROS:
- schema changes litlle easier
- backup and administration seems more robust

CONS:
- heard of vacuum problems
- connection pooling is hard, as 100 shards would mean 100 pools

So what is actually the right approach? If anyone could shed some light on
my issue.

*Thanks*