What Is PostgreSQL? – Kinsta

Currently, almost every web program or application requires a database on the backend. The increase in transactions per second and terabytes of data stored demands a stable and flexible framework for hosting and serving that data.

Naturally, for startups, the issue of cost also comes into the picture. But what if we told you that you can access and even build this database for free, with no strings attached?

Yes, you heard that right: the PostgreSQL database guarantees everything we’ve mentioned above, including some additional benefits! In this article, we’ll go over the various aspects of PostgreSQL that allow you to stay high in a rapidly evolving segment.

Let’s go to the bronze tacks.

Check out our video guide to understand


What is


The PostgreSQL logo, showing the text below a stylized blue elephant head outlined in black and white.PostgreSQL logo (
(Image source: Uberconf)) PostgreSQL

is an open source and highly stable database system that provides support for different SQL functions, such as foreign keys, subqueries, triggers, and different user-defined types and functions. It further extends the SQL language by offering several features that meticulously scale and reserve data workloads. It is mainly used to store data for many mobile, web, geospatial, and analytics applications.

We’ll delve into all aspects of PostgreSQL in this article, starting with its key features in the next section. Let’s get to work.

What if you could access and build a database at no cost, without strings attached? 👀 PostgreSQL could be the solution 🚀Click To Tweet Key Features of PostgreSQL

There are some key features of the PostgreSQL database that make it unique and widely favored compared to other databases. Currently, it is the second most used database, only behind MySQL.

Let’s take a look at these features in more detail.

Reliability and standards compliance

PostgreSQL offers true ACID semantics for transactions and has full support for foreign keys, joins, views, triggers, and stored procedures, in many different languages. It includes most SQL data types such as INTEGER, VARCHAR, TIMESTAMP, and BOOLEAN. It also supports storage of large binary objects, including images, videos, or sounds. It is reliable as it has a large community support network built in. PostgreSQL is a fault-tolerant database thanks to its write-ahead logging.

PostgreSQL Extensions

boasts several robust feature sets including point-in-time recovery, multiversion concurrency control (MVCC), tablespaces, granular access controls, asynchronous replication, a refined query scheduler/optimizer, and write-ahead logging. Multiversion concurrency control allows simultaneous reading and writing of tables, blocking only simultaneous updates of the same row. In this way, confrontations are avoided.


PostgreSQL supports Unicode, international character sets, multibyte character encodings, and recognizes locale for sorting, case-sensitivity, and formatting. PostgreSQL is highly scalable: in the number of concurrent users, it can accommodate as well as the amount of data it can manage. In addition, PostgreSQL is cross-platform and can run on many operating systems, including Linux, Microsoft Windows, OS X, FreeBSD, and Solaris.

Dynamic loading

The PostgreSQL server can also include user-written code itself through 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 needed. The ability to modify its operation on the fly makes it particularly suitable for deploying new storage structures and applications quickly.



The PostgreSQL server has a simple structure, consisting of a shared memory, background processes, and a data directory structure. In this section, we discuss each component and how they interact with each other. Below is an illustration of the PostgreSQL architecture. Initially, the client sends a request to the server. The PostgreSQL server then processes the data using shared buffers and background processes. The physical file of the PostgreSQL database server is stored in the data directory.

<img src="https://kinsta.com/wp-content/uploads/2022/02/postgresql-architecture.jpg" alt="The PostgreSQL architecture diagram,

showing the text below a hierarchy of blue PostgreSQL processes, outlined in black” />
PostgreSQL architecture illustration (Image source: Wikimedia Commons)


shared memory is reserved for transaction log caching and database caching. In addition, it has elements such as shared buffers, WAL buffers, working memory, and maintenance working memory. Let’s delve into each topic below.

Shared buffers

These buffers are used to minimize server disk I/O. To meet this goal, 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 for shared buffers starting with version 9.3 is 128 MB. It is imperative to try to minimize contention when multiple users access it simultaneously. Frequently used blocks should be buffered for as long as possible. This allows you to access the data as quickly as possible.

WAL buffers WAL buffers

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



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

Maintenance Working Memory

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

Background processes

Each background process is integral and performs a unique function for managing the server. Here are some important background processes:

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 up the shared buffer area. If the database crashes, data loss can be measured by getting the difference between the last checkpoint time and the PostgreSQL stop time.

Background writer process

Updates logs and backup information. Until version 9.1, this process was integrated with the checkpointer process that was performed regularly. However, starting with version 9.2, the checkpointer process was separated from the background writing process.

WAL Writer This process writes and flushes WAL data into the WAL buffer periodically into persistent storage.


If enabled, this process is responsible for copying the WAL log files

to a specified directory.

Registrar/Log Collector

This process writes a WAL buffer to the WAL file.

Data Files

/Data Directory Structure

PostgreSQL has several databases, together forming a database cluster. When initialized, the template0, template1, and Postgres databases are created. The creation of the new user database is done through template databases, which consist of the system catalog tables. Although the list of tables of template0 and template1 is the same after initialization, only the template1 database can create the objects that the user needs, therefore, the user database is created by cloning the template1 database.

The data required for the cluster is stored in the cluster data directory, which is also known as “PGDATA”. It consists of several subdirectories. Some important ones are mentioned below

: Global: The global subdirectory

  • consists of clustered tables, such as the user database. Base: The Base subdirectory
  • is the physical location of the default tablespace. It contains several subdirectories per database, within which system catalogs are stored.
  • PID: The PID file consists of the current 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 useful for troubleshooting.

Why use


In addition to providing a variety of features such as indexes, views, and stored procedures, PostgreSQL has much more to offer, namely:

Language Support


  • source object
  • relational
  • database performance

  • Extensibility Load balancing capabilities
  • Internationalization of reliability
  • Let’s examine them

in more detail

. Language


PL/PGSQL is a native procedural language provided by PostgreSQL that has different modern features. It supports 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.

It’s free and open source: This is by far the most significant benefit of PostgreSQL. It has been supported by over 20 years of community development, which in turn has contributed to its high level of integrity. Its source code is available under an open source license that allows you to use, modify, and deploy it as you see fit, at no additional cost.

Object-relational database

Objects, classes, and function overloading are directly supported by PostgreSQL. You can extend data types to create custom data types, due to their object-oriented features. This ensures high flexibility for developers operating with complex data models that require database integration.

Table inheritance is another feature supported by PostgreSQL due to its object-oriented features. The child table can inherit the columns from its parent table, in addition to the other columns owned by the child table, making it different from itself.


write operations

in PostgreSQL can be performed simultaneously without the need for 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 traverse all the data.

With PostgreSQL, you can even create an expression index, which works with the result of an expression or function instead of just the value of a column. Partial indexing, in which only a portion of the table is indexed, is also supported. It also supports parallelization of read queries, compilation of just-in-time (JIT) expressions, and nested transactions (via save points), ensuring high performance and efficiency.

PostgreSQL extensibility


highly extensible since its operation is catalog-based, i.e. information is stored in databases, columns, tables, etc. PostgreSQL not only contains a greater amount of information in your catalogs, but also details about data types, access methods, functions, etc. You can even go so far as to write your codes from different programming languages without recompiling your database, and define their data types.

Load balancing capabilities

Ensure high availability and load balancing through standby server operation, continuous planning, preparing primary servers for standby, configuring a standby server, streaming replication, replication slots, cascading replication, and standby continuous archiving. In addition, PostgreSQL supports synchronous replication, where two DB instances can run at the same time and the master database is synchronized with a slave database simultaneously, further ensuring high availability.

In addition

to storing data

securely and allowing the user to retrieve the data when the request is processed, it is backed by a community of contributors who regularly find bugs and try to improve the software, making PostgreSQL reliable



process of designing software so that it can be used in a variety of regions is known as internationalization. It supports international character sets through multi-byte character encodings, UCI collations, Unicode, and locale recognition for sorting, formatting, and case-sensitive. Viewing PostgreSQL-generated messages in the language of your choice is an example of internationalization.

When to use PostgreSQL

Do you need to create complex queries and relationships that need to be updated frequently and maintained consistently as cost-effectively as possible? PostgreSQL might be a suitable choice. PostgreSQL is not only free, but it is also cross-platform and not only limited to the Windows operating system. If you want to analyze data, PostgreSQL provides a large number of regular expressions as the basis for analytical work.

It is also one of the best databases when it comes to CSV support. Simple commands like “copy from” and “copy to” help in fast data processing. If there is an import problem, it will throw an error and stop the import immediately. The following sections will cover some of the most common PostgreSQL applications in the modern world. Start.


Geospatial Data

The PostGIS Geospatial Database Extension plugin for PostgreSQL is undoubtedly beneficial. When used in conjunction with the PostGIS extension, PostgreSQL supports geographic objects and can be used as a geospatial data store for geographic information systems (GIS) and location-based services.

PostgreSQL is an ideal DBMS system for the financial industry. Since it is fully compatible with ACID, it is an ideal choice for OLTP (online transaction processing) as these databases must be written, read, and updated frequently, along with an emphasis on fast processing. It is also suitable for running database analysis. It can be integrated with any software that performs mathematical operations such as Matlab and R.


data requires terabytes of data. It is imperative to handle data as efficiently as possible. PostgreSQL provides wonderful analytics and a powerful SQL engine. This helps to manage a large amount of data with ease.

Web technology websites often deal with hundreds or thousands of requests per second. If the developer is looking for a cost-effective and scalable solution, PostgreSQL would be the best choice. PostgreSQL can run dynamic websites and applications as part of a robust alternative to the LAMP stack, i.e. the LAPP stack. (Linux, Apache, PostgreSQL, PHP, Python and Perl)


startups and large enterprises use PostgreSQL as the primary data warehousing solution for Internet-scale products, solutions, and applications. Supply chain performance can be optimized by using this open source DBMS as a storage backend. As a result, this allows companies to reduce the cost of operating their business.


Operational Challenges

We’ve only sung the praises of PostgreSQL in this article so far, so it’s only fair that we show you a couple of shortcomings you might stumble upon when dabbling with PostgreSQL. Here are some operational challenges you may encounter during the PostgreSQL adoption process.

Lack of a mature database ecosystem: PostgreSQL

  • boasts one of the fastest growing communities, but unlike traditional database vendors, the PostgreSQL community does not have the comfort of a developed database ecosystem.
  • The Shortage of Expertise: PostgreSQL it is often combined with multiple databases, such as MongoDB. Now, every database needs specialized dexterity, and hiring technical staff with the desired PostgreSQL domain can be a difficult task to fill. Along with management tools for PostgreSQL, database experts and DevOps teams must address multiple databases from multiple vendors. This can be difficult to manage when you can’t switch between existing processes.
  • Inconsistency: Since PostgreSQL is an open source tool, different IT development teams within an organization can start leveraging it organically. This could lead to another hurdle: the lack of a single point of knowledge for all PostgreSQL instances within the IT environment. Another problem that could be caused by different teams trying to solve the same problem is duplication and redundancy.

Key PostgreSQL Alternatives

Here are some key PostgreSQL alternatives you can leverage for your WordPress website


MySQL logo


(Image source: Mecdata)

When you think of databases, your mind instantly turns to MySQL. It was a fairly ubiquitous option for developers for a long time before viable alternatives started to appear. It was used by more than 39% of developers in 2019. Even though it lacks the versatility of PostgreSQL, it can still be useful for various use cases like scalable web applications.

MySQL has been maintained by Oracle since its inception in 1995. Oracle also offers elite versions of MySQL with proprietary plugins, add-on services, extensions, and robust user support. To better understand MySQL, you need to better understand client-server models and relational databases. Simply put, your data is divided into several separate storage areas, also known as tables, rather than downloading everything onto a single large storage drive. This is the essence of a relational database.

In addition to being a reliable and solid database platform, it is quite easy to master. The learning curve is not as steep as some of its contemporaries, as you don’t need to have a full understanding of SQL to start working with MySQL.

If you leverage WordPress for your

website and want to understand how to make MySQL run faster, your best bet would be to refine your database to align with how you use WordPress. In technical terms, this is known as MySQL Performance Tune. The obvious advantage of optimizing MySQL is shorter load times along with an overall faster website. Apart from this, if you maintain your database properly, you should see a steady improvement in its growth, even as it expands.


The MariaDB logo, showing the text below a stylized brown sea lion outlined in blue.MariaDB logo
(Image source: Docker Hub)MariaDB

is a commercially supported fork of the MySQL relational database management system that takes a fundamentally different approach to meet the needs of the modern world. MariaDB’s purpose-built, pluggable storage engine supports workloads that previously required a wide range of specialized databases. This allows it to be a one-stop shop for organizations, whether in the cloud or on the commodity hardware they love.

You can deploy MariaDB in minutes for analytical, transactional, or hybrid use cases to deliver unmatched operational prowess without sacrificing key business features. This includes full SQL and actual ACID compliance.

MariaDB offers the following products to its users

: MariaDB Enterprise

  • : MariaDB Enterprise is an absolute, production-grade open source database solution that can address analytical, transactional, or hybrid analytical/transactional workloads with elegance. MariaDB Enterprise also has the ability to scale from columnar, standalone databases to fully distributed SQL databases that can perform millions of transactions per second. It also allows you to conduct interactive, improvised analysis across billions of rows.
  • MariaDB Community Server: MariaDB Community Server is the open source relational database leveraged by the vast majority of developers today. MariaDB Community Server not only supports Oracle, MySQL, and other databases, but also ensures that it will remain open source forever. Highlights include columnar storage for analytics, modern SQL, pluggable storage engines, and high availability.
  • MariaDB SkySQL: SkySQL is known as a database-as-a-service (DBaaS) offering that brings the full power of MariaDB Enterprise to the cloud along with its support for analytical, transactional and hybrid workloads. SkySQL is based on Kubernetes and has been revamped for cloud services and infrastructure. SkySQL has made a name for itself in this space by combining self-service and ease of use with top-notch support capabilities and enterprise reliability. Quite evident since the last statement, this comprises everything that is needed to securely run critical databases in the cloud alongside enterprise governance.

Because of its compatibility with MySQL, you can leverage MariaDB as a “substitute” for MySQL with virtually no consequences


Best practices for your database

When you’re thinking of beginner-friendly platforms for first-time website owners, you’re probably thinking of WordPress. WordPress allows you to accomplish a lot without any prior coding experience. However, to extract maximum value from WordPress, you still need to have a clear understanding of how some of its basic elements work. For example, if you’ve been using WordPress for your website for quite some time now, it’s probably a good time to understand how WordPress databases work.

This immediately prompts a common question, why does WordPress need a database after all? It may not seem like it, but there’s more to WordPress than meets the eye. There’s a lot of groundwork behind the scenes to make it work efficiently, regardless of the size of your website.

To dig deeper, you should know that a WordPress website is made up of many different types of data. It is now obvious that all this information is stored in a consolidated WordPress database. This database is integral to your WordPress website, saving all the changes you or your visitors make and allowing your website to run smoothly. Here is some data that is collected in your WordPress database:

  • Organizational information such as tags and categories
  • .

  • Site-wide configuration
  • .

  • Pages, posts and related content
  • .

  • Data related to themes and plugins
  • .

  • User comments and data.

When you install a WordPress website, part of the process is creating a database for it. Usually, this is done automatically. However, there is a provision if you want to create a database manually, or even leverage an existing database with a new website.

The next section will talk about best practices for your WordPress database.

Using a

database administration tool

The basic function of database administration tools is to allow you to view the contents of your database. For a database to run smoothly, leveraging a database management tool might be your best bet. In general, database management tools consolidate functions that meet the needs of three distinct database professionals


  • Database analysts can extract data from multiple sources. This is followed by cleaning, integrating and preparing the data for analysis. For database analysts, having the ability to collaborate on datasets and queries without having to rely on IT for access is an integral requirement.
  • Database developers need tools that allow them to write high-quality code the first time and maintain it smoothly. Database developers value collaboration and automation tools for programming. This allows them to condense development cycles without increasing risk.
  • Database administrators take advantage of tools designed to track database performance and health. They address tasks from unraveling and diagnosing performance bottlenecks to executing database schema changes.

When searching the market for a database management tool that

meets your business requirements, you should look for tools that can incorporate database testing, development, and deployment tasks into the continuous delivery and continuous integration process, making it easier to keep up with application development.

An effective database management tool should also allow data visualization of tabular results in graphs, histograms, and graphs, with easy distribution to decision makers. It should also help administrators locate problems before they occur in production by focusing on SQL statements and applications that don’t scale well with increased transaction volume.

Adminer (formerly known as phpMinAdmin) is a free open source database administration tool that offers tons of useful features and a sleeker user interface (UI). You can easily deploy this handy database management tool on your server, and all you need to do is upload your single PHP file, point your browser to it, and log in.


a database add-in

If you want to evaluate the quality of a website, look no further than your database. Every grain of information associated with your website finds its way into your WordPress database. Some of this is crucial, while some of it is only holding you back. This would include incorrect tables, old drafts, spam comments. To prevent them from hindering your website, you should incorporate WordPress database plugins.

Database plugins can come in various forms. Some plugins can be used to clean the database of junk files on a monthly or weekly basis. Other add-ons can be leveraged to back up your database before making changes, for example, during a migration. In addition to improving the speed of your website, you can use database plugins to provide a more efficient user experience while improving your chances of ranking higher in search engines.

Diagnosing and repairing your database

As a WordPress user, you’ve probably encountered a couple of annoying WordPress errors. Here is one of the most common error messages you may have encountered:

This means that the username and password information in your wp-config.php file is incorrect or we can
Error establishing a connection

The importance of fixing your database should be pretty obvious. Not only do WordPress errors hinder the proper functioning of your website, but they can also have a detrimental effect on the consumer experience. Failed installations and upgrades, downtime, and missing resources can take a toll on your revenue potential and damage your credibility.

Learn what PostgreSQL is and what sets it apart in a rapidly evolving segment in this post 🚀Click-to-Tweet


PostgreSQL is a free, open source relational database management system that focuses on SQL compliance and extensibility. Riding on the back of 30+ years of active development, PostgreSQL is one of the most widely used open source database tools worldwide.

In this article, we cover some of PostgreSQL’s most prominent features, PostgreSQL architecture, use cases, benefits, operational challenges, and key alternatives. We finish it with some best practices to keep your WordPress database in tip-top condition while continuing to scale.