SQLite to PostgreSQL -

In today’s business landscape, the traditional Relational Database Management model plays a crucial role for businesses across various industries. It serves as the backbone for managing transactional data. Typically, relational database engines are implemented as server processes, allowing programs on a system to communicate and exchange data. However, there is an alternative approach provided by the SQLite platform, which enables processes to directly access and manipulate the database stored in a Disk File, without the need for a dedicated server.

SQLite’s serverless nature, combined with its impressive processing speed, has gained significant popularity in the market today. While SQLite offers numerous advantages, it is often considered more suitable for lightweight applications. Consequently, developers often turn to PostgreSQL and other robust Relational Database Management Systems (RDBMS) for demanding tasks, particularly when building web applications. PostgreSQL, known for its ability to handle concurrent tasks effectively, has become a preferred choice for developers looking to optimize their workload by migrating data from SQLite to PostgreSQL.

This article aims to introduce you to the distinctive features of both SQLite and PostgreSQL. Additionally, we will delve into the process of connecting the two databases and seamlessly transferring data from SQLite to PostgreSQL. To better understand reasons and challenges of the migration, let us consider primary capabilities of both DBMS.

Key Features of SQLite

SQLite operates without the need for a dedicated server process or external system. It functions in a serverless manner, simplifying deployment and eliminating the overhead of server configuration and administration.
Setting up SQLite requires no complex configuration or administration. It requires less than 400KB of disk space, and the entire SQLite database can be stored in a single cross-platform file.
SQLite is self-contained and independent, meaning it doesn’t rely on external dependencies or additional software installations. This self-contained nature allows for easy distribution and deployment. SQLite transactions are also ACID-compliant, ensuring safe access and integrity of data, even when multiple threads are involved.
SQLite supports a wide range of query languages, encompassing most of the features present in the SQL2 standard. It is compatible with UNIX operating systems such as Linux, Mac OS-X, iOS, Android, as well as Windows operating systems like Win32, WinCE, and WinRT.

Key Features of PostgreSQL

PostgreSQL supports various data types and allows for extensive customization to suit specific requirements. Its monolithic architecture consists of components that facilitate automated interaction and provide advanced customization capabilities.
PostgreSQL seamlessly integrates with most popular operating systems, ensuring compatibility across different environments. It incorporates multiple fail-safe and backup methodologies, enhancing data reliability and minimizing the risk of data loss.
PostgreSQL enables businesses to accommodate growth by offering scalability options. The extent of scalability largely depends on the system (machine) used to run PostgreSQL, allowing flexibility in expanding resources to meet evolving demands.
PostgreSQL prioritizes data security with its robust access control mechanism, which operates at the level of rows and columns. It includes special security features and supports multi-factor authentication, leveraging high-standard certificates to ensure secure storage of data. This open-source tool emphasizes data protection and confidentiality.

Connecting SQLite to PostgreSQL

The most common and straight forward option to connect SQLite to PostgreSQL via Python special capability called Fixture. This method consisting of the following steps:

Create dumpdata backup for SQLite database
Create PostgreSQL database
Configure settings.py
Import the data from SQLite to PostgreSQL via loaddata

Run the following command line to generate the SQLite dump data in the JSON fixture format:

python manage.py dumpdata > whole.json

Install PostgreSQL on your system, create new user and database:

create user pgsuser;

create database mydb;

alter role hero with password ‘mydb@123’;

grant all privileges on database mydb to pgsuser;

alter database mydb owner to pgsuser;

Install Python support for PostgreSQL:

pip install psycopg2

Next step to connect SQLite to PostgreSQL is configuring the Setttings.py script. Create script settings.py as follows:

DATABASES = {

‘default’: {

‘ENGINE’: ‘django.db.backends.postgresql_psycopg2’,

‘NAME’: ‘mydb’,

‘USER’ : ‘pgsuser’,

‘PASSWORD’ : ‘mydb@123’,

‘HOST’ : ‘localhost’,

‘PORT’ : ‘5452’,

}

Do not forget to delete all service Python files from previous migrations:

find . -path “*/migrations/*.py” -not -name “__init__.py”

-delete

find . -path “*/migrations/*.pyc”

-delete do

Create a new migration file for each application:

python manage.py makemigrations

python manage.py migrate

Now everything is ready to load data to PostgreSQL database from fixtures via the following statement:

python manage.py loaddata fixture/whole.json

The fixture method mentioned earlier for connecting SQLite to PostgreSQL relies on significant RAM usage for loading data. Consequently, if your SQLite database contains more than 100MB of data, the method may encounter difficulties or experience performance issues. Therefore, to ensure a smooth and efficient transfer, it is advisable to execute the data migration process at the early stages of your projects.

SQLite to PostgreSQL Converter

The approach above may seems too complicated for end users having no skills in programming and database administration. For those users it is recommended to consider special tools designed to automate SQLite to PostgreSQL migration. One of these tools is SQLite to PostgreSQL converter developed by Intelligent Converters software vendor.

SQLite to PostgreSQL converter provides the following capabilities: