Reading from and Writing to a Delta Lake

In Chapter 3, Designing and Implementing the Data Exploration Layer, you first encountered the concept of a Delta Lake. This is a layer of relational tables, called delta tables, on top of the files stored in a data lake. While the ability to see data in a tabular format and use SQL to query is also offered by creating an external table over CSV or Parquet files, creating a delta table adds extra benefits, such as versioning and transaction support.

Note

This section primarily focuses on the Read from and write to a delta lake concept of the DP-203: Data Engineering on Microsoft Azure exam.

In Synapse, aside from creating delta tables from templates, as shown in Chapter 3, Designing and Implementing the Data Exploration Layer, you can also create custom tables, as shown in Figure 5.35:

Figure 5.35 – Creating a custom delta table in Synapse

Alternatively, you can create a delta table from an existing...