Querying Cross-System Analytics by Joining Data from a Delta Table and a Federated Data Source. DATA-ANALYST-ASSOCIATE Practice Questions (Page 3)

Questions 11–15

1. 11foundation · easy

   Which statement best describes how Databricks SQL queries a federated data source?

   • AIt only works with external systems that are hosted on the same cloud provider as Databricks.
   • BIt copies the entire external dataset into a Delta table before executing the query.
   • CIt uses a connection to the external system and translates the query into operations that the external system can execute.
   • DIt requires the external system to be migrated to the Databricks platform first.
   Reveal Solution Discussion Select an answer first
2. 12application · medium

   An analyst runs a query that joins a small Delta table (100 rows) with a large federated SQL Server table (10 million rows). The query filters the federated table on a non-indexed column. The analyst notices the query is slow. What is the best way to improve performance?

   • AUse a broadcast join hint to send the Delta table to all executors.
   • BAdd an index on the federated table's filter column in SQL Server.
   • CMove the filter to the Delta table side by pre-filtering the Delta table.
   • DIncrease the SQL warehouse size to handle more data.
   Reveal Solution Discussion Select an answer first
4. 13foundation · easy

   In a query that joins a Delta table and a federated data source, where do the tables appear in the SQL statement?

   • AIn the `SELECT` clause
   • BIn the `WHERE` clause
   • CIn the `FROM` and `JOIN` clauses
   • DIn the `GROUP BY` clause
   Reveal Solution Discussion Select an answer first
5. 14foundation · easy

   Which query is more likely to benefit from predicate pushdown when querying a federated data source?

   • AA query that selects all columns and all rows from the federated source.
   • BA query that filters rows using a WHERE clause on the federated source.
   • CA query that joins two Delta tables.
   • DA query that uses a window function.
   Reveal Solution Discussion Select an answer first
6. 15foundation · easy

   In Databricks SQL, what is a federated data source?

   • AA data source that is replicated to multiple cloud regions for high availability.
   • BA data source that is only accessible through a private network and requires a VPN connection.
   • CAn external system, such as a database or data warehouse, that Databricks SQL connects to and queries without importing the data into Databricks.
   • DA data source that is stored in the Databricks file system (DBFS) and managed by the metastore.
   Reveal Solution Discussion Select an answer first