ARA-R01 Exam Dumps : SnowPro Advanced: Architect Recertification Exam

Enabling the search optimization service on the table can improve the performance of queries that have selective filtering criteria, which seems to be the case here. This service optimizes the execution of queries by creating a persistent data structure called a search access path, which allows some micro-partitions to be skipped during the scanning process. This can significantly speed up query performance without increasing compute costs1.

References

•Snowflake Documentation on Search Optimization Service1.

An external table schema defines the columns and data types of the data stored in an external stage. All external tables include the following columns by default:

• VALUE: A VARIANT type column that represents a single row in the external file.
• METADATA$FILENAME: A pseudocolumn that identifies the name of each staged data file included in the external table, including its path in the stage.
• METADATA$FILE_ROW_NUMBER: A pseudocolumn that shows the row number for each record in a staged data file.

You can also create additional virtual columns as expressions using the VALUE column and/or the pseudocolumns. However, the following columns are not valid for external tables and cannot be included in the schema:

• METADATASROW_ID: This column is only available for internal tables and shows the unique identifier for each row in the table.
• METADATASISUPDATE: This column is only available for internal tables and shows whether the row was inserted or updated by a merge operation.
• METADATASEXTERNAL TABLE PARTITION: This column is not a valid column name and does not exist in Snowflake.

References: Introduction to External Tables, CREATE EXTERNAL TABLE

The image shows a SQL query that can be used to identify which queries are spilled to remote storage and suggests changing the warehouse parameters to address this issue. Spilling to remote storage occurs when the memory allocated to a warehouse is insufficient to process a query, and Snowflake uses disk or cloud storage as a temporary cache. This can significantly slow down the query performance and increase the cost. To troubleshoot this issue, a Snowflake Architect can run the query shown in the image to find out which queries are spilling, how much data they are spilling, and which warehouses they are using. Then, the architect can adjust the warehouse size, type, or scaling policy to provide enough memory for the queries and avoid spilling12. References:

• Recognizing Disk Spilling
• Managing the Kafka Connector