InfluxDB vs SQL Server

Choosing the right database is a critical choice when building any software application. All databases have different strengths and weaknesses when it comes to performance, so deciding which database has the most benefits and the most minor downsides for your specific use case and data model is an important decision. Below you will find an overview of the key concepts, architecture, features, use cases, and pricing models of InfluxDB and SQL Server so you can quickly see how they compare against each other.

The primary purpose of this article is to compare how InfluxDB and SQL Server perform for workloads involving time series data, not for all possible use cases. Time series data typically presents a unique challenge in terms of database performance. This is due to the high volume of data being written and the query patterns to access that data. This article doesn’t intend to make the case for which database is better; it simply provides an overview of each database so you can make an informed decision.

InfluxDB Overview

InfluxDB is a high-performance, time series database capable of storing any form of time series data, such as metrics, events, logs and traces. InfluxDB is developed by InfluxData and first released in 2013. InfluxDB is an open source database written in Go, with a focus on performance, scalability, and developer productivity. The database is optimized for handling time series data at scale, making it a popular choice for use cases involving monitoring performance metrics, IoT data, and real-time analytics.

InfluxDB 3.0 is the newest version of InfluxDB, currently available in InfluxDB Cloud Serverless and InfluxDB Cloud Dedicated. Built in Rust, a modern programming language designed for performance, safety, and memory management. InfluxDB also features a decoupled architecture that allows compute and storage to be scaled independently. InfluxDB 3.0 provides query support for both SQL and InfluxQL (custom SQL-like query language with added support for time-based functions).

SQL Server Overview

Microsoft SQL Server is a powerful and widely used relational database management system developed by Microsoft. Initially released in 1989, it has evolved over the years to become one of the most popular database systems for businesses of all sizes. SQL Server is known for its robust performance, security, and ease of use. It supports a variety of platforms, including Windows, Linux, and containers, providing flexibility for different deployment scenarios.

InfluxDB for Time Series Data

InfluxDB is specifically designed for time series data, making it well-suited for applications that involve tracking and analyzing data points over time. It excels in scenarios where data is being written continuously at high volumes while users also require the ability to query that data quickly after ingest for monitoring and real time analytics use cases.

SQL Server for Time Series Data

While Microsoft SQL Server is primarily a relational database, it does offer support for time series data through various features and optimizations. Temporal tables allow for tracking changes in data over time, providing an efficient way to store and query historical data. Indexing and partitioning can be leveraged to optimize time series data storage and retrieval. However, SQL Server may not be the best choice for applications requiring high write or query throughput specifically for time series data, as specialized time series databases offer more optimized solutions as well as a variety of developer productivity features that speed up development time for applications that heavily use time series data.

InfluxDB Key Concepts

• Columnar storage: InfluxDB stores data in a column-oriented format, using Parquet for persistent file storage and Apache Arrow as the in-memory representation of data. Columnar storage results in better data compression and faster queries for analytics workloads.
• Data Model: The InfluxDB data model will be familiar to anyone who has worked with other database systems. At the highest level are buckets, which are similar to what other systems call databases. InfluxDB measurements are synonymous with tables. Specific data points for a measurement contain tags and values. Tags are used as part of the primary key for querying data and should be used for identifying information used for filtering during queries. InfluxDB is schemaless so new fields can be added without requiring migrations or modifying a schema.
• Integrations: InfluxDB is built to be flexible and fit into your application’s architecture. One key aspect of this is the many ways InfluxDB makes it easy to read and write data. To start, all database functionality can be accessed via HTTP API or with the InfluxDB CLI. For writing data InfluxDB created Telegraf, a tool that can collect data from hundreds of different sources via plugins and write that data to InfluxDB. Client libraries are also available for the most popular programming languages to allow writing and querying data.
• Decoupled architecture: InfluxDB 3.0 features a decoupled architecture which allows query compute, data ingestion, and storage to be scaled independently. This allows InfluxDB to be fine-tuned for your use case and results in significant cost savings.
• Query Languages: InfluxDB can be queried using standard SQL or InfluxQL, an SQL dialect with a number of specialized functions useful for working with time series data.
• Retention Policies: InfluxDB allows you to define retention policies that determine how long data is stored before being automatically deleted. This is useful for managing the storage of high volume time series data.

SQL Server Key Concepts

• T-SQL: Transact-SQL, an extension of SQL that adds procedural programming elements, such as loops, conditional statements, and error handling, to the standard SQL language.
• SSMS: SQL Server Management Studio, an integrated environment for managing SQL Server instances, databases, and objects.
• Always On: A suite of high availability and disaster recovery features in SQL Server, including Always On Availability Groups and Always On Failover Cluster Instances.

InfluxDB Architecture

At a high level, InfluxDB’s architecture is designed to optimize storage and query performance for time series data. The exact architecture of InfluxDB will vary slightly depending on the version and how you deploy InfluxDB.

InfluxDB 3.0’s architecture can be broken down into four key components that operate almost independently from each other, allowing for InfluxDB to be extremely flexible in terms of configuration. These components are are data ingest, data querying, data compaction, and garbage collection. Data is written via the ingesters with millisecond latency. This data can be queried almost immediately by the data queriers while in the background the compactor takes the newly written data files and combines them into larger files that will be sent to object storage. The garbage collector is responsible for data retention and space reclamations by scheduling soft and hard deletion of data.

They key part of InfluxDB’s architecture is the separation of the ingest and query components, which allows each to be scaled independently depending on the current write and query workload. The querier being able to seamlessly pull in recently written data from the ingesters as well as from object storage allows data to be stored cheaply without increasing query latency.

SQL Server Architecture

Microsoft SQL Server is a relational database that uses SQL for querying and manipulating data. It follows a client-server architecture, with the database server hosting the data and processing requests from clients. SQL Server supports both on-premises and cloud-based deployment through Azure SQL Database, a managed service offering in the Microsoft Azure cloud. SQL Server’s architecture includes components such as the Database Engine, which processes data storage and retrieval, and various services for reporting, integration, and analysis.