How to Read Delta File in Databricks

BRIEF OVERVIEW

Databricks is a unified analytics platform that provides a collaborative environment for data scientists, engineers, and analysts. It supports various file formats including Delta Lake, which is an open-source storage layer that brings reliability and performance optimizations to cloud data lakes.

Delta files are stored in the Apache Parquet format and provide ACID transactions, schema enforcement, and metadata management capabilities. Reading delta files in Databricks is straightforward using the Delta Lake library.

FAQs

Q: How can I read a delta file in Databricks?

A: To read a delta file in Databricks, you need to follow these steps:

  1. Create a Spark session by importing necessary libraries.
  2. Load the delta file using the `spark.read.format(“delta”).load(path)` method.
  3. You can now perform various operations on the loaded dataframe such as filtering, aggregating, or transforming the data.
  4. To display the contents of the dataframe, use `display(dataframe)` or `dataframe.show()` methods.

Q: Can I specify additional options while reading a delta file?

A: Yes, you can pass additional options while loading a delta file. For example:

“`python
spark.read.format(“delta”)
.option(“mergeSchema”, “true”)
.load(path)
“`

This allows you to merge schemas if there are any changes between different versions of your delta table.

Q: What if my delta table has partitions?


A: If your delta table has partitions, you can leverage partition pruning to optimize query performance. Databricks automatically applies predicate pushdown and skips unnecessary data during query execution.

BOTTOM LINE

Reading delta files in Databricks is simple using the Delta Lake library. By following a few steps, you can load and manipulate delta files efficiently while benefiting from ACID transactions and schema enforcement capabilities provided by Delta Lake.