I tried to look into data dictionary of postgresql for long time but i didn't help.

I'm trying to know what state is the data file in, is it available for the db instance or not

photo with example

I tryed to look into pg_class table

CodePudding user response：

Postgres does not have the concept of "online" (or "offline") data files.

When you create a table it creates a file for that table. For every GB of data, Postgres will add a new file. If you drop the table all files belonging to that table are removed.

So the files for a table are always "online".

For more details on how Postgres stores the data, I recommend reading the chapter Database Physical Storage in the manual.

Or read The Internals of PostgreSQL - Chapter 1: Database Cluster, Databases, and Tables