10. Postgresql

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PostgreSQL

• Open source object-relational Database Management System(ORDBMS) that provides an implementation of the SQL querying language.

• Object-Oriented (Classes, inheritance)

• Featured Transaction Properties: ACID properties.

• having many advanced features like reliable transactions and concurrency without reading locks.

• Manages Concurrency

• RDBMS with client-server Architecture.

• Uses process per-user client/server Model. => Each user is granted/given a process that will remain alive till the user closes the connection.

• Programs run by the client connects to server instance & requests read and write operations.

• Relations = Table

• Tuple = Row

• Attribute = Column

• Default Port of PostgreSQL = 5432

• By Default Postgresql creates a database `Postgres

• Any select, insert, update, or delete to the data is done in the shared buffer area. The data is then written to data files located on a physical disk through background writer processes.

Installation on Linux

• Follow this tutorial

After Installation

• We got a command line Utility - psql.
  • Open terminal and enter psql
  • if not try sudo -i -u postgres then psql (this is switching over to the Postgres account on your server).
  • try \l command

Commands

Command	Description
\l	prints all databases list
\q	to quit
createuser --interactive	creating new role
createdb newdb	creating a new database with name newdb