What is Photon?
Applies to: Databricks SQL Databricks Runtime 9.1 and above
Learn about the advantages of running your workloads on Photon, the features it supports, and how to enable or disable Photon. Photon is turned on by default in Databricks SQL warehouses and is compatible with Apache Spark APIs, so it works with your existing code.
Photon is a high-performance Azure Databricks-native vectorized query engine that runs your SQL workloads and DataFrame API calls faster to reduce your total cost per workload.
The following are key features and advantages of using Photon.
- Support for SQL and equivalent DataFrame operations with Delta and Parquet tables.
- Accelerated queries that process data faster and include aggregations and joins.
- Faster performance when data is accessed repeatedly from the disk cache.
- Robust scan performance on tables with many columns and many small files.
- Faster Delta and Parquet writing using
CREATE TABLE AS SELECT, including wide tables that contain thousands of columns.
- Replaces sort-merge joins with hash-joins.
Get started with Photon
Photon is enabled by default on clusters running Databricks Runtime 9.1 LTS and above.
To manually disable or enable Photon on your cluster, select the Use Photon Acceleration checkbox when you create or edit the cluster.
If you create a cluster using the Clusters API, set
Photon supports a number of instance types on the driver and worker nodes. Photon instance types consume DBUs at a different rate than the same instance type running the non-Photon runtime. For more information about Photon instances and DBU consumption, see the Azure Databricks pricing page.
Operators, expressions, and data types
The following are the operators, expressions, and data types that Photon covers.
- Scan, Filter, Project
- Hash Aggregate/Join/Shuffle
- Nested-Loop Join
- Null-Aware Anti Join
- Union, Expand, ScalarSubquery
- Delta/Parquet Write Sink
- Window Function
- Comparison / Logic
- Arithmetic / Math (most)
- Conditional (IF, CASE, etc.)
- String (common ones)
- Aggregates(most common ones)
Features that require Photon
The following are features that require Photon.
- Predictive I/O for read and write. See What is predictive I/O?.
- H3 geospatial expressions. See H3 geospatial functions.
- Dynamic file pruning. See Dynamic file pruning.
- Structured Streaming: Photon currently supports stateless streaming with Delta, Parquet, CSV, and JSON. Stateless Kafka and Kinesis streaming is supported when writing to a Delta or Parquet sink.
- Photon does not support UDFs or RDD APIs.
- Photon doesn’t impact queries that normally run in under two seconds.
Features not supported by Photon run the same way they would with Databricks Runtime.