Implementing a dimensional hierarchy
As we have already explored dimensional hierarchy in Chapter 4, Designing the Serving Layer under the Designing a dimensional hierarchy section we will not be repeating it here. Please have a look at Chapter 4 to refresh your understanding of dimensional hierarchy.
Let's next look at the techniques available for reading and writing data in Parquet files.
Delivering data in Parquet files
In this section, we will learn to deliver data that is present in Parquet files via both Synapse SQL and Spark. We will use the concept of external tables that we learned in the previous chapter to accomplish this.
Let's consider an example where we have the trips
data stored as Parquet files. We will use Synapse SQL serverless pools and Spark to access the data and run some sample queries on it.
Synapse SQL serverless
Let's create an external table from within the Synapse SQL query editor that points to the Parquet files on the Azure...