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Difference between PostgreSQL and MongoDB

A foreign key can be one column or a group of columns that you can use to create a link in data from multiple tables at the same time. MongoDB aggregation pipelines are made up of multiple stages to transform data. Postgres uses GROUP_BY to run queries while MongoDB uses the aggregation pipeline. A schema is a template or structure you can apply to databases using a set vocabulary. The schema contains various schema objects, including tables, columns, keys, etc.

postgres vs mongo

It ensures isolation by providing different levels of transaction isolation from read committed to serializable. It ensures durability by writing changes to the disk before acknowledging a transaction commit. Constraints are rules used to limit the values that can be inserted into a column or set of columns in a table. For example, a primary key constraint ensures that each row in a table has a unique identifier, while a foreign key constraint ensures that a value in one table references a valid value in another table. PostgreSQL is an RBDMS based on a client-server model, where clients connect to the PostgreSQL server to access the database.

Get Support for Your Open Source Database

Open-source databases like PostgreSQL offer a cost-effective alternative as a stable production-grade database compared to its licensed contemporaries like SQL Server and Oracle. PostgreSQL, like Linux, is an example of a well-managed open source project. One of the most broadly adopted relational databases, PostgreSQL came out of the POSTGRES project at the University of California at Berkeley starting in 1986 and it has evolved with the times.

postgres vs mongo

PostgreSQL’s design principles place a heavy focus on SQL and relational tables, and allow considerable extensibility. This database provides a wealth of ways to enhance its efficiency, though it utilizes a scale-up strategy at its core. The object portion of this database relates to the varied extensions allowing it to incorporate alternative types of data, including JSON data objects, XML, and key/value stores. MongoDB relies on a distributed architecture allowing users to scale out across numerous instances. This scale-out approach depends on the use of a growing number of smaller, generally more cost-effective machines.

Use Cases and Factors Affecting the Choice of Postgres or MongoDB

It uses a relational model to store data in structured tables with predefined schemas, ensuring integrity through normalization. Having a different syntax and structure of data than relational database management systems (RDBMSs), it stores data in the form of documents. Additionally, as there’s no support for joins, MongoDB databases are oversupplied with data — sometimes duplicate — hence heavily burdening the memory. One of the most pivotal features of relational databases that make writing applications simpler is ACID transactions.

  • Contrast that with a SQL database where you must define its structure before you put data.
  • MongoDB also supports database transactions across many documents, so chunks of related changes can be committed or rolled back as a group.
  • Documents provide you with the ability to depict hierarchical relationships to store arrays and other more sophisticated structures easily.
  • It is actually a binary representation and the documents which bear a common structure are organized as collections.
  • It is because of the fact that the architecture of PostgreSQL is relational in nature.

If you already have a data model that is not going to change much, then PostgreSQL would be the best option. Essentially, it’s simpler for document databases to implement transactions as they keep data clustered in a document, and no multi-document transaction is required as document reading is an atomic process. One field or more might be written in just one operation, including updates to numerous sub documents and array elements.

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We’ve discussed their history, key features, and what makes them different. While PostgreSQL uses the GROUP_BY function to process and run aggregate queries MongoDB typically uses aggregation pipelines to process its queries. Data postgres vs mongo migration may also generate overhead; however, this is standard irrespective of the database you have implemented in your system. Hence anyone can use its features and make modifications to the code with ease when necessary.

postgres vs mongo

As a result, migrations between multiple clouds are more complicated. MongoDB Atlas performs in the same way across the three biggest cloud providers, ensuring easier migration and multi-cloud deployment. What makes MongoDB scalable is the concept of partitioning (sharing) data across instances within the cluster intelligently. This database doesn’t split documents into pieces — they’re independent units, which makes distributing them throughout various servers simpler, while the data is locally preserved.

PostgreSQL Use Cases

Data engineers can also build custom connectors in minutes for their unique use cases. PostgreSQL enforces a strict database schema where table structures must be defined upfront. They use SQL (Structured Query Language) for querying and manipulation. In addition to this, in a JSON array, there is no provision to update the fields if you are considering PostgreSQL. The entire document needs to be written to the database which creates a lot of issues.

MongoDB Atlas has been expanded via MongoDB Realm to make development of apps easier, through Lucene-powered Atlas Search. It has features supporting data lakes that have been built on cloud object storage. MongoDB has enjoyed widespread adoption as it has become the biggest modern database — it’s considered the go-to database by many developers.

ACID Properties and Transactions

This article aims to assist you in choosing the right type of database. Of course, one should wonder “maybe I chose the wrong document as the “outer.” What would happen if want to change to a design that makes Department the outer document. The benchmark has been tested on AWS, using an EC2 i3.xlarge instance (4 cores, 32 GB RAM), on a local NVMe disk formatted with XFS. Basic tuning was performed on the Postgres instance, and Mongo production best practices were followed. The benchmark was performed using 4000 departments and 20M employees, with a given employee working in between one and three departments. Data size was 6.1 GB in Postgres and 1.6GB in Mongo (using default compression).

With relational databases like PostgreSQL, altering your table is necessary to make any changes. The whole schema needs to be designed and configured at creation. You might be able to alter a table later on, but this may lead to database downtime and bugs in your application. PostgreSQL databases can use foreign keys which explicitly link data between tables and are used to keep the data normalized.

Performance Comparison of PostgreSQL vs. MongoDB

Users can perform a lot of tasks without worrying about anything. Also, it works perfectly fine and several JSON drivers are available for MongoDB which enhances functionality. There are certain challenges even in data scaling for those who consider PostgreSQL. There is a strict upper limit actually for distributing the database after a single node. Of course, this affects functionality and makes MongoDB useful than PostgreSQL when both of them are compared. MongoDB is quite reliable and users are always free to distribute the database to a number of nodes.

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