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 Kdb so you can quickly see how they compare against each other.

The primary purpose of this article is to compare how InfluxDB and Kdb 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 vs Kdb Breakdown


 
Database Model

Time Series Database

Time series and columnar database

Architecture

Cloud native architecture that can be used as a managed cloud service or self-managed on your own hardware locally

Kdb can be deployed on-premises, in the cloud, or as a hybrid solution.

License

MIT

Closed source

Use Cases

Monitoring, observability, IoT, real-time analytics

High-frequency trading, financial services, market data analysis, IoT, real-time analytics

Scalability

Horizontally scalable with decoupled storage and compute with InfluxDB 3.0 delivers up to 90% reduced storage costs( benchmarks )

Highly scalable with multi-threading and multi-node support, suitable for large-scale data processing

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Whether you are looking for cost savings, lower management overhead, or open source, InfluxDB can help.

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).

Kdb Overview

kdb+ is a high-performance columnar, time series database developed by Kx Systems. Released in 2003, kdb+ is designed to efficiently manage large volumes of data, with a primary focus on financial data, such as stock market trades and quotes. It is built on the principles of the q programming language, which is a descendant of APL and K. The database is known for its speed, scalability, and ability to process both real-time and historical data.


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.

Kdb for Time Series Data

kdb+ is designed to store time series data, making it a natural fit for applications that require high-speed querying and analysis of large volumes of data. Its columnar storage format allows for efficient compression and retrieval of time series data, while its q language provides a powerful and expressive means to manipulate and analyze the data. kdb+ is especially strong for financial data, though it can be used for other types of time series data as well.


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.

Kdb Key Concepts

  • q language: A high-level, domain-specific programming language used for querying and manipulating data in kdb+. It combines SQL-like syntax with a functional programming style.
  • Columnar storage: kdb+ stores data in columns, rather than rows, which allows for faster querying and analysis of time series data.
  • Tables: kdb+ stores data in tables, which are similar to relational tables, but with a focus on columnar storage and time series data.
  • Splayed tables: A table storage format where each column is stored in a separate file, further enhancing query performance.


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.

Kdb Architecture

kdb+ is a columnar, time series database that employs a custom data model tailored for efficient storage and querying of time series data. It does not use traditional SQL, but instead relies on the q language for querying and data manipulation. The architecture of kdb+ is designed for both in-memory and on-disk storage, with the ability to scale horizontally across multiple machines. The primary components of kdb+ are the database engine, the q language interpreter, and the built-in web server.

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InfluxDB Features

High-performance storage and querying

InfluxDB is optimized for time series data, providing high-performance storage and querying capabilities. In terms of storage InfluxDB is able to scale effortlessly due to its decoupled architecture. Object storage is used to persist data and query nodes can be scaled independently to improve query performance and capacity.

Compared to previous versions of InfluxDB, the newly released InfluxDB 3.0 compresses data 4.5x more effectively and queries are 2.5-45x faster depending on the type of query.

Retention policies

InfluxDB allows users to define retention policies that automatically delete data points after a specified duration. This feature helps manage data storage costs and ensures that only relevant data is retained.

Data compression

InfluxDB’s storage engine automatically compacts data on disk, reducing storage requirements and improving query performance. With InfluxDB 3.0 data is stored using the Parquet file format to get even higher compression ratios on time series data.

Horizontal scaling and clustering

InfluxDB supports horizontal scaling and clustering, allowing users to distribute data across multiple nodes for increased performance and fault tolerance.

Data tiering

InfluxDB 3.0 is able to seamlessly move data from cheap object storage into faster storage for low latency queries without expensive SSD or high amounts of RAM utilization. This allows users to store data for longer at higher frequencies while still saving in storage costs.

Kdb Features

High performance

kdb+ is known for its speed and performance, with its columnar storage format and q language allowing for rapid querying and analysis of time series data.

Scalability

kdb+ is designed to scale horizontally, making it suitable for handling large volumes of data across multiple machines.

q language

The q language is a powerful, expressive, and high-level language used for querying and manipulating data in kdb+. It combines SQL-like syntax with a functional programming style.


InfluxDB Use Cases

Monitoring and alerting

InfluxDB is widely used for monitoring and alerting purposes, as it can efficiently store and process time series data generated by various systems, applications, and devices. With its high-performance query engine and integration with visualization tools like Grafana, users can create real-time dashboards and set up alerts based on specific conditions or thresholds.

IoT data storage and analysis

Due to its high write and query performance, InfluxDB is an ideal choice for storing and analyzing IoT data generated by sensors, devices, and applications. Users can leverage InfluxDB’s scalability and retention policies to manage large volumes of time series data, and use its powerful query languages to gain insights into the IoT ecosystem.

Real-time analytics

InfluxDB’s performance and flexibility make it suitable for real-time analytics use cases, such as tracking user behavior, monitoring application performance, and analyzing financial data. With its support for InfluxQL and SQL, users can perform complex data analysis and aggregation in real-time, enabling them to make data-driven decisions.

Kdb Use Cases

Financial data analysis

kdb+ is widely used in the financial industry for the storage and analysis of stock market trades, quotes, and other time series financial data.

High-frequency trading

kdb+ is a popular choice for high-frequency trading applications due to its high performance and ability to handle large volumes of real-time data.

IoT and sensor data

kdb+ can be used to store and analyze large volumes of time series data generated by IoT devices and sensors, though its primary focus remains on financial data.


InfluxDB Pricing Model

InfluxDB offers several pricing options, including a free open source version, a cloud-based offering, and an enterprise edition for on-premises deployment:

  • InfluxDB Cloud Serverless: InfluxDB Cloud Serverless is a managed, cloud-based offering with a pay-as-you-go pricing model. It provides additional features, such as monitoring, alerting, and data visualization. InfluxDB Cloud is available across all major cloud providers.
  • InfluxDB Cloud Dedicated - This is a managed cloud solution that provides an isolated InfluxDB instance on dedicated hardware for use cases that require isolation or benefit from being able to specify and fine-tune hardware configuration.
  • InfluxDB Enterprise: On-prem solution with enterprise features for security and support for clustering and other horizontal scaling options.
  • InfluxDB Open Source: The open source version of InfluxDB is free to use and provides the core functionality of the database.

Kdb Pricing Model

kdb+ is a commercial product, with pricing depending on the deployment model and the number of cores or servers used. Kx Systems offers a free 32-bit version of kdb+ for non-commercial use, with limitations on the amount of memory that can be used. For commercial deployments and full-featured versions, users must contact Kx Systems for pricing details.