Can NoSQL Database be Transactional?
Many NoSQL databases are now able to serve as a transactional database. A brief history of NoSQL & ACID compliance and what dbs support it.
NoSQL databases started gaining traction and interest around 2006, making them 15 years old. When they started, they could not serve as a transactional database. That meant looking to relational databases anytime you needed transactional DB resources.
But like all technology, NoSQL is ever-evolving and building out new use cases. Some NoSQL databases can now serve as transactional databases but be careful when selecting one as not all include these features.
Get insights into what a transactional database is, changes to NoSQL databases to allow for transactions, and the options available to you when building out transactional applications.
What Is a Transactional Database?
The average technology user probably thinks little about how they are able to perform simple tasks.
Take the example of a social media platform. The user knows only what they see, which is a simple interface displaying posts from friends, family and their favorite brands.
What is happening in the background requires highly sophisticated databases. Without a database, all those social media posts, the profile images for each user and the timestamps for when they took place can’t exist.
Transactional databases are database management systems (DBMS). A transaction is any data manipulation instruction or inquiry to access or write data. With transactions, you can extract or modify large data volumes with incredible ease.
In its simplest form, a data transaction is the saving, altering or controlling of data within a system. These transactions cannot harm the data’s integrity, which means that while writing the data in real-time, you also need to be able to present accurate data in real-time.
The data that a transactional database manages could be preferences, purchase data or even information like a social media post.
Transactional DBs generally have these three key features.
- Data accuracy: transactional DBs are generally ACID compliant (this stands for atomicity, consistency, isolation and durability). That means that they can preserve large volumes of data accuracy in real-time. Historically, ACID compliance is one place where NoSQL databases have struggled. But new developments are helping overcome this to the point where some NoSQL databases can be ACID compliant.
- Data durability: Transactional databases ensure durability of the data and in case of any failure/crash the db is able to recover the data and brings the database back to the normal state. This is very critical when it comes to dealing with financial, accounting, (etc.) data.
- Flexible: users can edit data without touching other areas of other critical data sets. You can edit data without harming the system’s architecture. Users can easily pull transactional history even when data is housed in a limited context. NoSQL databases are far more flexible than relational databases, so this is not a challenge for this technology.
- Speed: complete transactions in milliseconds with a transactional database. Speed should not be an issue when using one of these databases as you should be able to create queries and write data at incredible speeds. Speed is one of the greatest strengths of NoSQL databases, so it’s no surprise that these databases can meet this need.
Ultimately, overcoming the ACID compliance need is the greatest hurdle for making NoSQL databases serve as transactional databases.
Up until recently, the best transactional databases were relational databases, including SQLite, Oracle, MySQL and Microsoft Access. But now let’s look into how NoSQL is changing to meet these needs for real-time data integrity and accuracy.
Changes to NoSQL Databases to Allow for Transactions
NoSQL databases have never been databases without SQL. NoSQL actually stands for “not only SQL.” That makes these databases excellent for housing structured, unstructured and semi-structured data all in one place while taking advantage of the scalability of NoSQL databases.
But the first 10 years or so of NoSQL databases was dedicated to getting data architects and IT teams on board with the idea of a new way of data modeling. The industry had to understand the value of these highly scalable databases. And IT teams had to understand that users could query some data without transactional guarantees while any lost data could be re-computed back from raw data later.
As adoption of NoSQL databases increased and the industry saw how non-relational databases could aid in creating internet-scale user-facing applications despite durability and scaling challenges, NoSQL began to develop new functionality.
Without ACID transactions in NoSQL databases, many applications used SQL databases and NoSQL side-by-side. The transactional data went to the SQL database and high-volume data where data loss was acceptable went to the NoSQL database.
And while this workaround ensured the application could capture all data, it made for challenging sharding requirements between the two databases. Plus, building out these applications took far longer than development teams wanted.
As NoSQL databases improve, data consistency is allowing it to be transactional. In BangDB, all single API calls are ACID, allowing it to serve as a transactional database.
Options Available for NoSQL Transactional DBs
When evaluating NoSQL transactional DBs, you want to primarily look for ACID compliance. Several NoSQL databases now handle ACID compliance. We’ll explain which ones to help you in finding the best transactional DB for your application.
BangDB is a multi-model NoSQL database that will keep up with your modern application needs as they develop and change. It supports stream processing for real-time continuous data intelligence so that you can ingest and process data for predictive data analytics.
And, the NoSQL database supports full ACID transactions. It implements optimistic concurrency control (OCC) and uses simple APIs to manage transactions.
BangDB Works Well as a Transactional solution?
This open source database powers many web and mobile applications. It allows for single-shard transactions with ACID guarantees. The system does support multi-document ACID transactions. According to MongoDB, its transactions have four limitations.
- It doesn’t read from system collections
- It doesn’t write to capped collections
- It doesn’t write to collections that are already created
- It can’t modify or drop collections or indexes
RavenDB was the first to offer a NoSQL database with ACIDicity across entire clusters. While transactions are distributed, they are still ACID compliant. It uses a custom-built storage engine that it calls Voron. It rolls all calls into one package to simplify the ACID transaction process to ensure performance.
However, some users report that the analytic capabilities in RavenDB are not as good as they could be and that large scale complex data updates present challenges. Additionally, many companies that rely on RavenDB do so by leaning on a few key developers, which can present challenges in managing applications.
Using a NoSQL Database for ACID Transactions
With so much development in NoSQL databases, they are becoming ideal to rely on for your transactional needs. And because they scale well and offer incredible affordability, it’s no surprise that many developers are looking to these databases as a solution for their transactional needs.