Creates a new connection pool with parameters.

default database=postgres.

HealthCheckPeriod is the duration between checks of the health of idle connections.

default host=127.0.0.1.

TODO: with hook level.

MaxConnIdleTime is the duration after which an idle connection will be automatically closed by the health check.

MaxConnLifetime is the duration since creation after which a connection will be automatically closed.

MaxConnLifetimeJitter is the duration after MaxConnLifetime to randomly decide to close a connection.

MaxConns is the maximum size of the pool.

MinConns is the minimum size of the pool.

default port=5432.

default ssl_mode=disable.

default user=postgres.

TODO: with hook level.

TODO: with hook level.

Function for passing connection parameters.