To understand the AWS RDS architecture overview & components

What is an RDS?

- RDS is a server that includes the database, we just start and use the service we need not worry about components.

- Its a server itself which got own features.

Components of RDS:

1.EC2- Elastic Cloud Compute:

- Its a server for RDS and meant for RDS purpose only.


- On top of EC2 we have DB software

- Being a client /user we don’t have any authority to work with EC2 / DBS services.

- We can specify the configuration of EC2 and DBS

Under the Postmaster PID file uses in PostgreSQL

  • As per the PostgreSQL architecture, the postmaster is the first background process that will starts when the cluster is started.
  • It is a parent process of all other background processes.
  • In case any of the other background processes got failed, The postmaster automatically restart the dead processes.
  • It also works as a listener. When the client’s request to the server first it will land into the postmaster and perform syntax and semantic checking, Once it is pass and spawn a new connection this process called “Pgprocess”.
  • The postmaster act as a listener…

Understand the difference between wal keep segments and replication slots.

WAL Keep Segment vs Replication slots

What is WAL?

  • WAL stands for Write ahead log
  • It is a log file that contains changes made on the database cluster, which mainly used for database consistency.
  • By using WAL files, we can replay either as part of the database recovery process when a database isn’t shut down correctly or we can also use the WAL logs to replay the changes to replicate to the standby databases.

What are WAL Keep Segments?

  • The specified number of past WAL logs are maintained under the PG_WAL subdirectory.
  • In the streaming replication…

To Understand the uses of initdb and default databases

  • It will create a new PostgreSQL cluster.
  • In Postgres cluster is a collection of databases that are managed by a single cluster.
  • It will create the data directories in which the database data will live, generating the shared catalog tables and creating default databases.

* Postgresql — used for connections

* template 0 — user connection is not allowed and maintain DB consistency

* template 1 — When we creating a database will take an exact copy of template1.

  • In case the user doesn’t have permission on the data directory will…

To Understand The Fork process will run different ID with the same Postmaster ID

Forking Process in Postgresql
  • It is a process of creating the child process that looks similar to the parent process that created it. The child process is known as “Forking”.
  • Both parent and child process has the same code of segments with a different address space.
  • The Forking Process (a) child process has a different process ID.
  • As per the PostgreSQL architecture, the postmaster is the first background process that will starts when the cluster is started. Based on the postmaster ID other background utility processes details are given below.

To Understand The Importance of WAL Writer Process and See The Demo Result of Manually Killing WAL Writer Process

The PostgreSQL architecture is a client-server architecture, when the client is requesting the server will respond to it. The core was RDBMS so it will supports the SQL and NoSQL data.

The architecture contains

  1. Instance
  2. Background process
  3. Database
    i)Physical structure
    ii)Logical structure


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