Postgres

Data types

Type	min	max	comment
boolean
char(n)
varchar(n)
text
smallint	-32768	32767
int
serial			(~auto_increment in mysql)
float(n)
real / float8
numeric(p,s)
date
time
timestamp
timestamptz
interval
json
jsonb
uuid
+ special

List all databases

SELECT datname FROM pg_database
WHERE datistemplate = false;

List all tables

SELECT table_catalog,table_schema,table_name FROM information_schema.tables 
WHERE table_type = 'BASE TABLE' AND table_schema = 'public' 
ORDER BY table_type, table_name

List all users

SELECT * FROM pg_user;