What is ClickHouse?
ClickHouse is an open source columnar database developed by Yandex. It is used for online analytical processing (OLAP) and known for managing large volumes of data with high performance. ClickHouse achieves this by storing data in a compressed format and executing queries directly on the compressed data.
This allows for fast query execution and efficient storage usage, making it suitable for environments where rapid data analysis and minimal latency are critical. ClickHouse is known for its high throughput and low response times, especially in real-time analytics scenarios.
ClickHouse supports SQL queries and offers compatibility with various data formats, contributing to its flexibility and ease of integration. The database provides horizontal scalability, allowing it to handle increasing data volumes by distributing load across multiple nodes. Its ability to process billions of rows per second helps optimize analytical workloads.
Key features of ClickHouse
Column-Oriented Storage
ClickHouse stores data by columns rather than by rows. In a column-oriented layout, values from the same column are stored together on disk. This design is highly efficient for analytical queries because most OLAP workloads read only a small number of columns from very large tables. Instead of scanning entire rows, ClickHouse reads only the required columns, reducing disk I/O and improving query speed.
Columnar storage also improves data compression. Since values in the same column often share similar patterns and data types, compression algorithms work more effectively. Better compression reduces storage costs and allows more data to fit into memory and cache layers. This combination of reduced storage usage and faster reads is one of the main reasons ClickHouse performs well on large analytical datasets.
High-Performance Analytics
ClickHouse is optimized for high-speed analytical processing on large volumes of data. The database uses vectorized execution, which processes batches of rows together instead of one row at a time. It also executes queries in parallel across CPU cores, allowing complex aggregations and filtering operations to complete quickly even on tables containing billions of records.
The system is designed for workloads such as reporting, observability, business intelligence, and event analytics. Functions for aggregation, grouping, and time-series analysis are heavily optimized. ClickHouse can process large scans and calculations with low latency, making it suitable for dashboards and applications that require near-instant analytical responses.
Real-Time Data Processing
ClickHouse supports high-speed data ingestion and near real-time querying. Data inserted into tables becomes available for analysis almost immediately, allowing organizations to analyze logs, metrics, transactions, and user events with minimal delay. This makes the database useful for monitoring systems, fraud detection, and operational analytics platforms.
The database integrates well with streaming systems such as Apache Kafka and Redpanda. These integrations allow ClickHouse to continuously consume and process event streams without requiring complex batch pipelines. Combined with fast query execution, this enables real-time dashboards and alerting systems that rely on continuously updated data.
SQL Support
ClickHouse supports SQL as its primary query language, making it accessible to developers, analysts, and data engineers. Users can perform filtering, sorting, joins, aggregations, subqueries, and window functions using familiar SQL syntax. This reduces the learning curve for teams migrating from traditional relational databases or data warehouses.
The database also includes SQL extensions designed for analytical workloads. These extensions provide functions for arrays, time-series analysis, approximate calculations, and statistical operations. Because of its SQL compatibility, ClickHouse integrates easily with business intelligence tools, reporting platforms, and data visualization systems.
Distributed Query Execution
ClickHouse supports distributed deployments that span multiple servers or clusters. Data can be partitioned and replicated across nodes, allowing the system to scale horizontally as storage and processing requirements grow. Distributed tables enable queries to run across all nodes in parallel, significantly improving performance for large datasets.
The distributed architecture also improves availability and fault tolerance. If one node becomes unavailable, replicated data can still be accessed from other nodes in the cluster. This design allows organizations to build highly scalable analytical systems capable of handling increasing workloads without relying on a single machine.
Materialized Views
Materialized views in ClickHouse automatically process and store transformed or aggregated data during insertion. Instead of calculating expensive aggregations every time a query runs, the database precomputes results and stores them in a separate table. This improves query performance for frequently accessed reports and dashboards.
Materialized views are commonly used for rollups, metrics aggregation, and data transformation pipelines. For example, raw event data can be automatically aggregated into hourly or daily summaries as it enters the database. This reduces query complexity and lowers computational overhead during analysis, especially in real-time analytics environments.
Limitations of ClickHouse
While ClickHouse offers some advantages, it also comes with limitations that users should be aware of. These limitations were reported by users on the G2 platform:
- Steep learning curve for advanced usage: Multiple users reported that ClickHouse can be difficult for beginners, especially when working with data modeling, partitioning, sharding, replication, and query optimization. Advanced features often require deeper expertise to use effectively.
- Complex query optimization: Some reviewers noted that optimizing complex analytical queries is not always straightforward. Achieving the best performance may require careful schema design and tuning strategies.
- Resource-intensive infrastructure requirements: Users mentioned that ClickHouse may require larger servers to maintain high performance at scale. Some organizations may need to rely on cloud deployments, which can increase operational costs.
- Limited support for data updates and modifications: Editing or updating existing records can be cumbersome. ClickHouse is optimized for analytical workloads rather than transactional update-heavy operations.
- Deduplication management challenges: One reviewer highlighted issues with deduplication strategies and limited visibility into how deduplication processes are handled internally.
- Materialized view limitations: Although materialized views improve performance, users reported that they can be difficult to configure for complex use cases. Some users also noted limitations around joins in materialized views.
- Operational complexity in distributed environments: Users experienced difficulties managing distributed features such as ZooKeeper integration, replication, and sharding configuration.
- Documentation gaps for advanced scenarios: While the documentation is generally considered strong, some reviewers felt that advanced use cases could be explained in more detail to simplify onboarding and troubleshooting.
- Limited extensibility for custom functions: Some users reported that the ability to create custom functions is limited compared to other database systems.
ClickHouse vs open source alternatives
ClickHouse operates on an open source license, which means users and organizations like NetApp Instaclustr are free to use, contribute updates and patches, and offer managed services for ClickHouse under a different logo.
Although ClickHouse is currently open source, there is always a risk that the founding company will revoke its open source license and change it to a commercial license. Most recent examples of this include Redis revoking its open source license in 2024 and Elasticsearch switching to a commercial license in 2021, leading to the forking and creation of open source Valkey and OpenSearch, respectively.
Related content: Read our guide to ClickHouse vs Elasticsearch
Tips from the expert
Suresh Vasanthakumar
Site Reliability Engineer
Suresh is a seasoned database engineer with over a decade of experience in designing, deploying and optimizing high-performance distributed systems. Specializing in in-memory data stores, Suresh has deep expertise in managing Redis and Valkey clusters for enterprise-scale applications.
In my experience, here are tips that can help you better evaluate and utilize alternatives Instaclustr for ClickHouse for OLAP and real-time analytics:
- Define workload-specific requirements: Clearly identify whether the workload requires high-speed ingestion, complex analytics, or scalability across distributed environments. This helps in choosing the right alternative that aligns with specific needs.
- Evaluate schema flexibility: For use cases with frequently evolving data models, prioritize systems like Snowflake or Databricks, which support both structured and semi-structured data seamlessly.
- Assess real-time capabilities: If real-time analytics or streaming ingestion is critical, tools like Google BigQuery or ScyllaDB excel in handling live data without performance degradation.
- Test query performance on large datasets: Use sample datasets representative of production workloads to benchmark query latency and throughput across candidates, focusing on the most complex queries.
- Check compatibility with existing tools: Ensure the database integrates well with the current analytics stack, such as BI tools, ETL pipelines, or machine learning workflows. This minimizes the overhead of adapting infrastructure.
Notable ClickHouse alternatives
Managed Data Platforms and Data Warehouses
1. Instaclustr Managed ClickHouse
Instaclustr for ClickHouse delivers a powerful, fully-managed solution for organizations looking to harness the speed and efficiency of real-time data analytics that is 100% open source. Built specifically for performance at scale, ClickHouse is known for its ability to handle massive volumes of data with unparalleled query speeds. By choosing Instaclustr’s managed service, businesses can unlock the full potential of ClickHouse without the challenges of deployment, operations, and ongoing maintenance.
License: Apache 2.0 (fully open source)
Key features include:
- Fully managed service: Instaclustr manages everything from deployment to scalability, security, monitoring, and updates.
- Optimized performance: Instaclustr ensures ClickHouse delivers lightning-fast queries and efficient data storage, even at high scale.
- Secure and reliable: Enterprise-grade encryption, automated backups, and 24/7 system monitoring provide the reliability and security businesses need to trust their data operations.
- Seamless scalability: Instaclustr makes it simple to scale resources up or down as data needs evolve, ensuring consistent performance without downtime.
- Open source foundation: Built entirely on open source technology, Instaclustr for ClickHouse avoids vendor lock-in, aligning with broader technology strategies.

2. Google Cloud BigQuery
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Google Cloud BigQuery is a fully managed, serverless data warehouse for large-scale analytics and data processing. It separates compute and storage resources, allowing organizations to scale analytics workloads independently without managing infrastructure. BigQuery supports structured and unstructured data, integrates with multiple data sources, and provides capabilities for machine learning, geospatial analysis, streaming ingestion, and governance.
License: Commercial
Key features include:
- Serverless architecture: BigQuery removes the need to provision or manage infrastructure. Compute and storage resources scale automatically based on workload requirements.
- Separation of compute and storage: Storage and analytics layers operate independently, reducing resource contention and allowing flexible scaling.
- Columnar storage engine: Data is stored in a column-oriented format optimized for analytical queries and compression efficiency.
- Streaming and batch ingestion: BigQuery supports continuous streaming ingestion as well as batch loading from formats such as Parquet, ORC, Avro, CSV, and JSON.
- ANSI SQL support: The platform supports standard SQL with joins, aggregations, window functions, nested fields, and geospatial operations.
- Federated querying: Users can query external data sources such as Cloud Storage, Bigtable, Spanner, and Google Sheets without moving data into BigQuery.

Source: Google Cloud
3. Snowflake
Snowflake is a cloud-native data platform for analytics, data engineering, AI workloads, and data sharing. The platform provides managed storage and compute resources with support for transactional and analytical workloads on the same system. Snowflake emphasizes cross-cloud interoperability, governance, scalability, and integrated support for AI and collaboration workflows.
License: Commercial
Key features include:
- Fully managed platform: Snowflake handles infrastructure management, scaling, maintenance, and performance updates automatically.
- Separation of storage and compute: Compute resources can scale independently from storage, allowing flexible workload management.
- Cross-cloud deployment: The platform supports deployments and collaboration across multiple cloud providers and regions.
- Unified data and AI platform: Snowflake supports analytics, transactional processing, AI, and application workloads within a single environment.
- Built-in governance and security: Features include enterprise-grade security, access controls, observability, compliance management, and disaster recovery.
- Support for open table formats: Snowflake supports Iceberg tables and cross-engine access to open data formats.

Source: Snowflake
4. Amazon Redshift

Amazon Redshift is a cloud data warehouse service for SQL analytics on large-scale datasets. It supports analytics across data warehouses, data lakes, and federated data sources while offering serverless deployment options and integrations with AWS analytics and AI services. Redshift is optimized for distributed query execution and scalable analytical processing.
License: Commercial
Key features include:
- Managed cloud data warehouse: Redshift provides managed infrastructure for analytical workloads with automatic scaling and maintenance capabilities.
- Serverless deployment option: Redshift Serverless allows users to run analytics workloads without provisioning or managing clusters.
- Distributed SQL analytics: The platform executes analytical queries across distributed resources for large-scale processing.
- Integrated data lake querying: Redshift can query data stored in Amazon S3 and open formats such as Apache Iceberg and Parquet.
- Near real-time analytics: Zero-ETL integrations support near real-time analysis from operational databases and streaming systems.
- Integration with AWS ecosystem: Redshift integrates with Amazon SageMaker, Bedrock, and other AWS services for analytics and AI workflows.

Source: Amazon
5. Databricks

Databricks is a data and AI platform built around lakehouse architecture, combining data engineering, analytics, machine learning, and AI workflows in a unified environment. The platform provides tools for ETL, streaming, governance, business intelligence, and AI development while supporting open data formats and distributed processing.
License: Commercial
Key features include:
- Lakehouse architecture: Databricks combines data lake and data warehouse capabilities within a unified platform.
- Unified data and AI workflows: The platform supports data engineering, analytics, machine learning, and AI application development.
- Natural language capabilities: AI-powered interfaces simplify querying, data discovery, code generation, and workflow development.
- Integrated governance and security: Databricks provides centralized governance, privacy controls, and security features for data and AI workloads.
- Real-time streaming support: The platform supports continuous data ingestion and stream processing pipelines.
- Open ecosystem support: Databricks integrates with open technologies such as Apache Spark, Apache Iceberg, and Delta Lake.

Source: Databricks
Databases and Distributed Systems
6. DuckDB
DuckDB is an in-process analytical SQL database for local analytics and embedded data processing. It runs directly inside applications without requiring a separate database server and supports querying files, cloud storage, and structured datasets using SQL. DuckDB is intended for analytical workloads with a columnar execution engine and lightweight deployment model.
License: MIT
Key features include:
- Embedded database architecture: DuckDB runs inside applications without requiring a separate server process.
- Columnar execution engine: The database uses a column-oriented engine optimized for analytical query performance.
- Direct file querying: DuckDB can query formats such as Parquet and JSON directly without importing data into tables.
- Cloud storage integration: The platform supports querying data stored in systems such as Amazon S3 and data lakes.
- SQL support: DuckDB provides a SQL interface for analytical processing and aggregation workloads.
- Lightweight deployment: The database can be installed and embedded quickly with minimal operational overhead.

Source: DuckDB
7. ScyllaDB
ScyllaDB is a distributed NoSQL database for low-latency and high-throughput workloads. It is compatible with Apache Cassandra and Amazon DynamoDB APIs and uses a shard-per-core architecture to maximize hardware efficiency. ScyllaDB is optimized for distributed deployments, fault tolerance, and scalable write-heavy applications.
License: AGPL-3.0
Key features include:
- Shard-per-core architecture: Each CPU core independently manages its own memory and storage resources to reduce contention and improve performance.
- Distributed peer-to-peer design: All nodes operate without a central leader, eliminating single points of failure.
- Cassandra and DynamoDB compatibility: ScyllaDB supports Cassandra Query Language (CQL) and DynamoDB APIs.
- Horizontal scalability: Clusters can scale across multiple nodes and geographic regions.
- Wide-column data model: The database uses a partitioned wide-column model optimized for distributed workloads.
- Replication and fault tolerance: Data can be replicated across nodes and datacenters for resilience and availability.

Source: ScyllaDB
8. CockroachDB

CockroachDB is a distributed SQL database for cloud-native applications requiring high availability, geographic distribution, and horizontal scalability. It is PostgreSQL-compatible and supports deployments across cloud, hybrid, and on-premises environments. The database focuses on resilience, consistency, and operational simplicity for transactional workloads.
License: Proprietary
Key features include:
- Distributed SQL architecture: CockroachDB distributes data and queries across multiple nodes while maintaining SQL compatibility.
- PostgreSQL compatibility: Applications can interact with CockroachDB using PostgreSQL interfaces and tooling.
- Automatic horizontal scaling: The database scales across nodes without requiring manual sharding.
- High availability and resilience: The system supports automated failover, strong consistency, and regional fault tolerance.
- Cloud-agnostic deployment: CockroachDB can run across public cloud, hybrid, and on-premises environments.
- Geographic data placement controls: Declarative policies allow organizations to store data in specific regions for compliance and latency optimization.

Source: CockroachDB
Conclusion
When selecting a database for analytics and data processing, it is important to consider the specific requirements of your use case, including performance, scalability, ease of integration, and operational complexity. It is critical to evaluate each tool in the context of workload demands, team expertise, and long-term business goals. A well-chosen database can optimize workflows, improve decision-making, and adapt to evolving data needs over time.