PostgreSQL | A Powerful Object-Relational Database System

For your information, PostgreSQL has earned a strong reputation for its proven architecture, reliability, data integrity, robust feature set, extensibility, and dedication to the open-source community, especially behind the software that consistently delivers performant and innovative solutions. Nowadays, almost every software or web application requires a database in the backend.

The increase of transactions occurring per second and the terabytes of data stored calls for a stable and flexible framework for housing and serving up that data. For startups, the issue of cost also comes into the picture. What if we told you that you can access and even build this database free of charge, with no strings attached? Yes, that’s right—the PostgreSQL database is everything.

Including a few extra perks!  The origins of PostgreSQL date back to 1986 as part of the POSTGRES project at the University of California at Berkeley. As of today, it has more than 30 years of active development on the core platform. It’s important to realize that PostgreSQL is a noncommercial, all-volunteer, free software project. And as such, there is no formal list of features.

Or rather, there are no requirements for development. At the same time, it allows developers to explore their chosen topics. Although they also ensure that all new features committed to PostgreSQL are thoroughly vetted. By a community of contributors and committers. With that in mind, let’s learn more about what the PostgreSQL platform offers webmasters in detail.

Getting To Know What PostgreSQL Platform Is All About To Data Experts

To enumerate, PostgreSQL is a powerful, open-source object-relational database system that uses and extends the SQL language—combined with many features that safely store and scale the most complicated data workloads. Eventually, PostgreSQL runs on all major operating systems and has been ACID-compliant since 2001, with powerful downloadable database software add-ons.

It’s powered by downloadable database software add-ons such as the popular PostGIS geospatial database extender. Unsurprisingly, PostgreSQL has become the open-source relational database of choice for many people and organizations. In other words, PostgreSQL is an open-source, highly stable database system that provides support for different functions of SQL.

Such as foreign keys, subqueries, triggers, and different user-defined types and functions. It further augments the SQL language proffering up several features that meticulously scale and reserve data workloads. It’s primarily used to store data for many mobile, web, geospatial, and analytics applications. A few key features of the PostgreSQL database make it unique.

And some of them are widely favored when compared to other databases. Currently, it’s the second-most used database, only falling behind MySQL Database and other related add-ons.

Why Use PostgreSQL?

PostgreSQL tries to conform with the SQL Standard, where such conformance does not contradict traditional features or could lead to poor architectural decisions. Many of the features required by the SQL standard are supported. Though sometimes with slightly differing syntax or function. Further moves towards conformance can be expected over time.

Its version 12 release in October 2019 conforms to at least 160 of the 179 mandatory features for SQL. With 2016 Core conformance as well. As of this writing, no relational database fully complies with this standard. PostgreSQL offers actual ACID semantics for transactions and fully supports foreign keys, joins, views, triggers, and stored procedures, in many different languages.

How The PostgreSQL Server4 Works

It includes most data types of SQL like INTEGER, VARCHAR, TIMESTAMP, and BOOLEAN. It also supports the storage of large binary objects, including pictures, videos, or sounds. It is reliable as it has an extensive built-in community support network. PostgreSQL is a fault-tolerant database thanks to its write-ahead logging.

The project aims to make at least one minor quarterly release on a predefined schedule. If it becomes necessary due to a critical bug fix or security issue, more release updates will be made between these dates. So this list should be considered a minimum. A new minor release will be made for each supported version at each date, and the most recent version will be released to the market.


It’s free and open-source — this is by far the most significant benefit of PostgreSQL. It has been backed by more than 20 years of community development, contributing to its high integrity level. Its source code is available under an open-source license that allows you to use, modify and implement it however you see fit – at no extra cost. Objects, classes, and function overloading are directly supported in PostgreSQL. Extending data types to create custom data types is possible due to their object-oriented characteristics. This guarantees high flexibility for developers operating with complex data models that require database integration.


PL/PGSQL is a native procedural language provided by PostgreSQL which has different modern features. It backs the JSON data type, which is lightweight and ensures the flexibility included in a single package. As a result, PostgreSQL supports several programming languages and protocols, including Perl, Ruby, Python, .Net, C/C++, Java, ODBC, and Go. Table inheritance is another feature supported by PostgreSQL due to its object-oriented characteristics. The child table can inherit the columns from its parent table and the other columns that the child table possesses, making it different from itself.


In addition to storing data securely and allowing the user to retrieve it when the request is processed, it is backed by a community of contributors that regularly find bugs and try to improve the software, making PostgreSQL reliable. Write operations in PostgreSQL can be performed concurrently without needing read/write locks. Indexes are used to speed up queries when dealing with large amounts of data, allowing databases to find a specific row without having to cycle through all the data.


It guarantees high availability and load balancing through standby server operation, continuous planning, preparing the primary for standby servers, setting up a standby server, streaming replication, replication slots, cascading replication, and constant archiving in standby. Additionally, PostgreSQL supports synchronous replication, where two database instances can run simultaneously, and the master database is synchronized with a slave database simultaneously, further ensuring high availability.


PostgreSQL boasts several robust feature sets, including point-in-time recovery, Multi-Version Concurrency Control (MVCC), tablespaces, granular access controls, asynchronous replication, an advanced query planner/optimizer, and write-ahead logging. Multi-Version Concurrency Control allows for concurrent reading and writing of tables, blocking only contemporary updates of the same row. This way, clashes are avoided. It also promotes parallelization of reading queries, Just-in-time (JIT) compilation of expressions, and nested transactions (via savepoints), ensuring excellent performance and efficiency.


PostgreSQL supports Unicode, international character sets, and multi-byte character encodings, and it is locale-aware for sorting case sensitivity and formatting. PostgreSQL is highly scalable — in the number of concurrent users, it can accommodate the quantity of data it can manage. Furthermore, PostgreSQL is cross-platform and can run on many operating systems, including Linux, Microsoft Windows, OS X, FreeBSD, and Solaris.


The PostgreSQL server can also include user-written code into itself via dynamic loading. The user can specify an object code file; for example, a shared library that implements a new function or type, and PostgreSQL will load it as required. The ability to modify its operation on the fly uniquely suits it to implement new storage structures and applications rapidly. With PostgreSQL, you can create an expression index, which works on the result of an expression or a function rather than just the value of a column. Partial indexing is also supported, wherein only a part of the table is indexed.


PostgreSQL is highly extensible as its operation is catalog-driven, i.e., information is stored in databases, columns, tables, etc. PostgreSQL not only holds an increased amount of information in its catalogs but also details on the data types, access methods, functions, and so on. You can even go as far as to write your codes from different programming languages without recompiling your Database and defining your data types.


The process of designing software for various regions is known as internationalization. It supports international character sets through multi-byte character encodings, ICU collations, and Unicode, and it is locale-aware for sorting formatting and case sensitivity. Viewing PostgreSQL-generated messages in the language of your choice is an example of Internationalization.

Which Are The Main Server Features And Processes?

Remarkably, PostgreSQL is among the most popular databases out there. The main advantage of PostgreSQL is it is open-source. Also, it is robust with high performance and multitasking. This database also includes many features that make it one of the good choices out of all the databases. PostgreSQL has become better with its every release.

The PostgreSQL Server has a simple structure consisting of Shared Memory, Background Processes, and a Data Directory structure. In this section, we discuss each component and how they interact. Given below is an illustration of the PostgreSQL architecture. Initially, a request is sent by the client to the server. Then, the PostgreSQL server processes data.

The Main PostgreSQL Server Features And Processes

In that case, it processes data using shared buffers and background processes. The physical file of the PostgreSQL database server is stored in the data directory. PostgreSQL has several databases, together forming a database cluster. When initialized, template0, template1, and Postgres databases are created. The new database creation of the user is done through template databases.

Eventually, which consists of the system catalog tables, and although the list of tables in template0 and template1 is the same after initialization, only the template1 database can create the objects the user needs; hence the user database is created by cloning the template1 database.

1. Shared Memory

The shared memory is reserved for transaction log caching and database caching. It has elements like Shared Buffers, WAL Buffers, Work Memory, and Maintenance Work Memory. Let’s dive into each topic below.

2. Shared Buffers

These buffers serve to minimize the server DISK IO. To fulfill this objective, it is fair to set the value of the shared buffer as 25% of the total memory if we have a dedicated server for PostgreSQL. The default value of the shared buffers from version 9.3 onwards is 128 MB. It is imperative to try and minimize the contention when several users access it simultaneously. Frequently used blocks should be in the buffer for as long as possible. This allows it to access the data as quickly as possible.

2. WAL Buffers

WAL buffers temporarily store changes to the database. The WAL file consists of contents written by the WAL buffer at a predetermined point in time. WAL files and WAL buffers are significant in recovering data during backup and recovery.

3. Work Memory

This memory space is used for bitmap operations, sorting, merging joins, and hash joins to write data into temporary disk files. The default setting from version 9.3 onwards is 4 MB.

4. Maintenance Memory

This memory slot is used for database operations such as ANALYZE, VACUUM, ALTER TABLE, and CREATE INDEX. The default setting from version 9.4 onwards is 64 MB.

5. Background Processes

Each background process is integral and performs a unique server management function. A few essential background processes are further elaborated below:

6. Checkpointer Process

When a checkpoint occurs, the dirty buffer is written to the file. The Checkpointer essentially writes all dirty pages from memory to disk and cleans the shared buffer area. If the database crashes, data loss can be measured by obtaining the difference between the last checkpoint time and PostgreSQL stopped time.

7. Background Writing

It updates logs and backup information. Until version 9.1, this process was integrated with the checkpointer process, which was done regularly. However, from version 9.2 onwards, the checkpointer process was separated from the background writer process.

8. WAL Writer

This process periodically writes and flushes the WAL data on the WAL buffer to the persistent storage.

9. Archiver Process

This process is responsible for copying the WAL log files to a specified directory if enabled.

10. Collector Process

The Logger/Logging Collector process writes a WAL buffer to the WAL file. The data needed for the cluster is stored within the cluster’s data directory, also called “PGDATA.” It consists of several subdirectories. A few important ones are mentioned below.

Such as follows:
  • Global: The global subdirectory consists of cluster-wise tables such as the user database.
  • Base: The Base subdirectory is the physical location of the default tablespace. It contains several per-database subdirectories, within which the system catalogs are stored.
  • PID: The PID file contains the postmaster process ID (PID).
  • PG_VERSION: This subdirectory consists of the database version information.
  • PG_NOTIFY: This subdirectory contains the LISTEN/NOTIFY status data. These files can be helpful for troubleshooting.

Be that as it may, we hope we all are familiar with the term Database. And for interacting with the database, what we need is called SQL( Structured query language). You should know about this database as a software developer or engineer. Also, if you want to learn this database, you must make your hands dirty. It comes with many features aimed to help you in various ways.

Such as follows:
  1. developers build applications,
  2. administrators to protect data integrity and create fault-tolerant environments, and
  3. help you manage your data no matter how big or small the dataset.

In addition to being free and open-source software, PostgreSQL is highly extensible. For example, you can define your data types and build custom functions. As well as you can even write code from different programming languages without recompiling your database! A PostgreSQL database developer is working on the project, not someone using it to develop an app or a website.

For one thing, they don’t hire programmers. Instead, they reach across the Internet, drawing the best database developers in the world to PostgreSQL. With this in mind, read more about the people behind PostgreSQL and check out the group picture from the 2006 PostgreSQL Anniversary Summit. Below is an inexhaustive list of various features found in PostgreSQL.

  • Data Types

    • Primitives: Integer, Numeric, String, Boolean
    • Structured: Date/Time, Array, Range, UUID
    • Document: JSON/JSONB, XML, Key-value (Hstore)
    • Geometry: Point, Line, Circle, Polygon
    • Customizations: Composite, Custom Types
  • Data Integrity

    • Primary Keys
    • Foreign Keys
    • Exclusion Constraints
    • Explicit Locks, Advisory Locks
  • Concurrency, Performance

    • Indexing: B-tree, Multicolumn, Expressions, Partial
    • Advanced Indexing: GiST, SP-Gist, KNN Gist, GIN, BRIN, Covering indexes, Bloom filters
    • Sophisticated query planner/optimizer, index-only scans, multicolumn statistics
    • Transactions, Nested Transactions (via savepoints)
    • Multi-Version Concurrency Control (MVCC)
    • Parallelization of reading queries and building B-tree indexes
    • Table partitioning
    • All transaction isolation levels defined in the SQL standard, including Serializable
    • Just-in-time (JIT) compilation of expressions
  • Reliability, Disaster Recovery

    • Write-ahead Logging (WAL)
    • Replication: Asynchronous, Synchronous, Logical
    • Point-in-time-recovery (PITR), active standbys
    • Tablespaces
  • Security

    • Authentication: GSSAPI, SSPI, LDAP, SCRAM-SHA-256, Certificate, and more
    • Robust access-control system
    • Column and row-level security
    • Multi-factor authentication with certificates and an additional method
  • Extensibility

    • Stored functions and procedures
    • Procedural Languages: PL/PGSQL, Perl, Python (and many more)
    • SQL/JSON path expressions
    • Foreign data wrappers: connect to other databases or streams with a standard SQL interface
    • Customizable storage interface for tables
    • Many extensions that provide additional functionality, including PostGIS
  • Internationalization, Text Search

    • Support for international character sets, e.g., through ICU collations
    • Case-insensitive and accent-insensitive collations
    • Full-text search

Given its immediate roadmap release updates, there are many more features that you can discover in the PostgreSQL documentation and other related resource references. Additionally, PostgreSQL is highly extensible: many features, such as indexes, have defined APIs so you can build out with PostgreSQL to solve your challenges.

How Do You Backup Your PostgreSQL Database?

It is an actual database engine, and SQL is a programming language with which we are working to communicate with a database. This is an object-relational database, meaning the relationship between the two tables is maintained. Any database has a table format that is integrated with rows and columns.

On the contrary, PostgreSQL Supports many data types, such as string, numeric, date, and time like My SQL. Also, it supports data types for geometric shapes, images, network addresses, bit strings, text searches, JSON entries, etc.  You can read and understand its Database Architecture to gather more helpful information.

PostgreSQL Architecture

For instance, if you are using PostgreSQL in a production environment, it is essential to take precautions to ensure that your users’ data is not lost. By frequently backing up your database and automating backups with a cron task, you can quickly restore your system if your database is lost or corrupted.

Fortunately, PostgreSQL includes tools to make this task simple and easy to manage. You should have a working installation of PostgreSQL on your system before beginning backup. Go through the How to Install PostgreSQL on Ubuntu guide to install PostgreSQL and create a sample database. You can also learn to back up a PostgreSQL Database with pg_dump in detail.

Summing Up,

The first place to go for any questions on PostgreSQL is its world-renowned documentation which discusses how to use the database software in-depth. They also have many mailing lists where you can connect and participate in the community—as well as many events and local user groups where you can connect with other users.

PostgreSQL has been proven to be highly scalable in the sheer quantity of data it can manage and the number of concurrent users it can accommodate. Active PostgreSQL clusters in production environments tend to have many terabytes of data. And it also has specialized systems that manage petabytes. Finally, we hope the above-revised guide on PostgreSQL was practical enough.

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