Databases(2)

db Databases(2)#

In pgAdmin, Databases (2) means:

The PostgreSQL server currently contains 2 databases.

Just like:

  • Servers (1)

  • Login / Group Roles (12)

  • Tablespaces (2)

The number in parentheses always represents a count.

What is a Database in PostgreSQL?#

A database in PostgreSQL is:

  • A logical container

  • That holds:

  • Schemas

  • Tables

  • Views

  • Functions

  • Indexes

  • Data

Each database is isolated from others.

Objects inside one database cannot directly access objects in another database.

Why pgAdmin shows Databases (2)

Databases (2)
|__ MyDB
└── postgres
This means:

  • Only two databases exists on this PostgreSQL server

  • It was likely:

  • Created manually by you, or

  • Created automatically during installation

Many systems show 2 databases by default:

  • postgres

  • A custom database

But in my case, there are only two, so pgAdmin correctly shows (2).

Relationship: Server → Database → Objects

This hierarchy is very important:

Server
└── Database
      └── Schema
         └── Tables / Views / Functions
So:

  • Server = PostgreSQL engine instance

  • Database = logical workspace

  • Schema = namespace inside database

🔐 Databases and Roles (Users)#

Each database:

  • Has an owner (a role)

  • Uses role permissions for access

Example:

  • Role sherullahmohtat owns the database

  • Other roles may have read/write access

This connects directly to Login / Group Roles (12).

Databases and Tablespaces#

Databases store their data in:

  • A tablespace

By default:

  • pg_default tablespace is used

So the chain becomes:

Tablespace → Database → Schema → Table

Note

Summary

Databases are logical containers in PostgreSQL that store schemas, tables, and data, isolated from other databases on the same server.

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