Return connections to the master database

[gedl]

One use case of a database cluster is by an application with a heavy bias towards reads.
In this case, the master database can be mostly idle

This task is to implement a configurable mechanism where the user specifies whether (/how much) a connection to the writer instance should be returned, additionally to the read round-robin.

[ballen-bw]

I would also like to see this enhancement. We use the dice-fairlink driver for a read-only application but would like to be able to send connections to the writer too since it is very underutilized, which translates to a waste of thousands of dollars depending on the size. The writer instance must be kept at a large size in order to utilize autoscaling since the autoscaled instances are always created at the same size as the writer. Even if it was just a basic option to enable/disable connections to the writer, that would be very helpful and seems like it would be fairly easy to implement.