Query pruning in Snowflake is the mechanism used to limit the number of micro-partitions scanned by a query. By analyzing the filters and conditions applied in a query, Snowflake can skip over micro-partitions that do not contain relevant data, thereby reducing the amount of data processed and improving query performance. This technique is particularly effective for large datasets and is a key component of Snowflake's performance optimization features.
Reference:
Snowflake Documentation: Query Performance Optimization

To use the overwrite option on insert in Snowflake, the DELETE privilege must be granted to the role. This is because overwriting data during an insert operation implicitly involves deleting the existing data before inserting the new data.
* Understanding the Overwrite Option: The overwrite option (INSERT OVERWRITE) allows you to replace existing data in a table with new data. This operation is particularly useful for batch-loading scenarios where the entire dataset needs to be refreshed.
* Why DELETE Privilege is Required: Since the overwrite operation involves removing existing rows in the table, the executing role must have the DELETE privilege to carry out both the deletion of old data and the insertion of new data.
* Granting DELETE Privilege:
* To grant the DELETE privilege to a role, an account administrator can execute the following SQL command:
sqlCopy code
GRANT DELETE ON TABLE my_table TO ROLE my_role;
Reference: For additional details on inserting data with the overwrite option and the required privileges, consult the Snowflake documentation on data loading: https://docs.snowflake.com/en/sql-reference/sql/insert.
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Scaling up the virtual warehouse in Snowflake involves increasing the compute resources available for a single warehouse, which can improve the performance of large and complex queries by providing more CPU and memory resources. Reference: Based on general cloud data warehousing knowledge as of 2021.

Snowpipe data load history is retained for 64 days. This retention period allows users to review and audit the data load operations performed by Snowpipe over a significant period of time, which can be crucial for troubleshooting and ensuring data integrity.
Reference:
[COF-C02] SnowPro Core Certification Exam Study Guide
Snowflake Documentation on Snowpipe1