PostgreSQL Concepts: Difference between revisions
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===Master User=== | ===Master User=== | ||
An administrative user that exists when the RDBMS instance is created and that has privileges to create other database and other users. It is used to bootstrap the administration of the RDBMS instance. The RDS documentation refers to it as "Master username". | An administrative user that exists when the RDBMS instance is created and that has privileges to create other database and other users. It is used to bootstrap the administration of the RDBMS instance, by defining all users, objects, and permissions in the databases of your DB instance. Master Username must start with a letter. The RDS documentation refers to it as "Master username". | ||
==Role== | ==Role== |
Revision as of 04:00, 9 September 2020
Internal
Connection Types
Local Socket
This is the default type of connection, then the psql client is collocated with the database.
TCP
The default port is 5432.
Database
A PostgresSQL usually comes with 4 pre-existing databases (postgres, admin, template0, template1). "postgres" is fit for general use and it should be used by default.
Database Name Case Sensitivity
Verify this:
It seems that the database name is case sensitive, even if a database is created with "CREATE DATABASE TEST_DB", the database name becomes "test_db", and this is what it should be used in the connect URL. "jdbc:postgres://localhost/test_db" will work, but "jdbc:postgres://localhost/TEST_DB" won't.
Schema
Each database has by default a public schema.
Tablespace
Authentication
User
Users are shared across databases.
The "user" concept is equivalent with the "role" concept. They mean the same thing.
Master User
An administrative user that exists when the RDBMS instance is created and that has privileges to create other database and other users. It is used to bootstrap the administration of the RDBMS instance, by defining all users, objects, and permissions in the databases of your DB instance. Master Username must start with a letter. The RDS documentation refers to it as "Master username".
Role
The "role" concept is equivalent with the "user" concept. They mean the same thing.
Role Attributes
A specific role may:
- be a superuser
- create another role
- create a database
Data Types
Identity
- http://www.postgresqltutorial.com/postgresql-identity-column/
- http://www.postgresqltutorial.com/postgresql-serial/
Timestamp
Numeric Types
SMALLINT
2 byte integer.
INT
4 byte integer. This is a typical choice for integers.
BIGINT
8 byte integer.
DECIMAL
NUMERIC
REAL
DOUBLE PRECISION
SERIAL
BIGSERIAL
TODO