Thank you very much, got it. > On 28 Dec 2018, at 11:36 PM, Alvaro Herrera <alvherre@xxxxxxxxxxxxxxx> wrote: > > Hello > > On 2018-Dec-28, ZongtianHou wrote: > >> I get somehow confused when I learn about namespace here, there are two questions, >> First, what is the difference between namespace and schema? > > None. Schema is the user-visible name for the feature; namespace is the > source code and system catalog level. > >> Second, why the Oid of public namespace is 2200, the same between >> databases? > > Not necessarily. That's the initial value, but it's possible to drop > the public schema and create it afresh. > >> Does oid is unique for every object across cluster? > > No, only inside each individual catalog are OIDs guaranteed unique. > >> Does someone know about these clearly? > > Yes. > > -- > Álvaro Herrera https://www.2ndQuadrant.com/ > PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services >
