amazon web services - creating a public postgress AWS database -

im trying create postgres rds database on aws that's accessible public without need ssh tunnelling. development only. i've created separate aws vpc , assigned gateways , 2 subnets it. when created database set public. security group rules are

inbound(custom tcp rule,tcp 5432,0.0.0.0/0) outbound (all traffic,all,all,0.0.0.0/0)

i can't seem connect database local pgadmin.

did enable vpc attributes have dns hostnames , dns resolution enabled? these must set in order db instance publicly accessible.