SnowPro Core Certification COF-C02 Updated Exam

 The STRIP_OUTER_ARRAY file format option in Snowflake is used when loading JSON documents that are composed of a large array containing multiple records. When this option is enabled, it removes the outer array structure, which allows each record within the array to be loaded as a separate row in the table. This is particularly useful for efficiently loading JSON data that is structured as an array of records1.

References:

• Snowflake Documentation on JSON File Format
• [COF-C02] SnowPro Core Certification Exam Study Guide

 Micro-partitions in Snowflake are immutable objects, which means once they are written, they cannot be modified. This immutability supports the use of Time Travel, allowing users to access historical data within a defined period. Additionally, micro-partitions can significantly reduce the amount of I/O from object storage to virtual warehouses. This is because Snowflake’s query optimizer can skip over micro-partitions that do not contain relevant data for a query, thus reducing the amount of data that needs to be scanned and transferred.

References: [COF-C02] SnowPro Core Certification Exam Study Guide

https://docs.snowflake.com/en/user-guide/tables-clustering-micropartitions.html

When the COPY INTO command is executed in Snowflake, it processes all files present in the specified stage that have not been ingested before or marked as already loaded. Since the user did not remove the original 10 files after the first load, running the same COPY INTO command again will result in all 20 files being processed. This means that the data from the original 10 files will be appended to the table again, along with the data from the new 10 files, potentially leading to duplicate records for the original data set.

References:

• Snowflake Documentation on Data Loading
• SnowPro® Core Certification Study Guide

 When unloading data to a stage, it is recommended to define an individual file format. This ensures that the data is unloaded in a consistent and expected format, which can be crucial for downstream processing and analysis2