Free Snowflake COF-C02 Practice Exam with Questions & Answers | Set: 7

 Snowflake recommends creating separate warehouses for each workload to resolve performance issues caused by shared virtual warehouses. This ensures that the resources are not being overutilized by one user’s activities, thereby affecting the performance of another user’s activities4.

To address query concurrency issues, a user can add additional clusters to the virtual warehouse. This allows for the distribution of queries across multiple clusters, reducing the load on any single cluster and improving overallquery performance2.

The parameter that prevents streams on tables from becoming stale is MAXDATAEXTENSIONTIMEINDAYS. This parameter specifies the maximum number of days for whichSnowflake can extend the data retention period for the table to prevent streams on the table from becoming stale4.

To execute a series of SQL statements using a task, a user would use a stored procedure that contains multiple SQL statements and invoke this stored procedure from the task. References: Snowflake Documentation2.

The details section of a Query Profile in Snowflake provides users with various statistics and information about the execution of a query. One of the key pieces of information that can be determined from this section is the total duration of the query, which helps in understanding the performance and identifying potential bottlenecks. References: [COF-C02] SnowPro Core Certification Exam Study Guide

The Snowflake object that helps evaluate virtual warehouse performance impacted by query queuing is the Information_schema.warehouse_load_history. This view provides historical data about the load on a warehouse, including the average number of queries that were running or queued within a specific interval, which can be used to assess performance and identify potential issues with query queuing3.

 Directory tables in Snowflake are used to store metadata about data files in a stage. They are not separate database objects but are conceptually similar to external tables. Directory tables do not have grantable privileges of their own

Pruning in Snowflake refers to the process of filtering or disregarding micro-partitions that are not needed to satisfy the conditions of a query. This optimization technique helps reduce the amount ofdata scanned, thereby improving query performance

During a query on a virtual warehouse, the columns in the result set of the query are cached. This allows for faster retrieval of data if the same or a similar query is run again, as the system can retrieve the data from the cache rather than reprocessing the entire query. References: [COF-C02] SnowPro Core Certification Exam Study Guide

 Snowflake supports several semi-structured data formats for loading data. The supported formats include JSON, Avro, and Parquet12. These formats allow for efficient storage and querying of data that does not conform to a traditional relational database schema.

 Snowflake data providers can share data residing in different databases through secure views. Secure views allow for the referencing of objects such as schemas, tables, and other views contained in one or more databases, as long as those databases belong to the same account. This enables providers to share data securely and efficiently with consumers. References: [COF-C02] SnowPro Core Certification Exam Study Guide

 The maximum Time Travel retention period for a transient table in Snowflake is 1 day. This is the default and maximumduration for which Snowflake maintains the historical data for transient tables, allowing users to query data as it appeared at any point within the past 24 hours2.

 To grant a role the privilege to select data from all current and future tables in a schema, two separate commands are needed. The first command grants the SELECT privilege on all existing tables within the schema, and the second command grants the SELECT privilege on all tables that will be created in the future within the same schema. 

For continuous data loads using Snowpipe, the recommended compressed file size range is between 100-250 MB. This size range is suggested to optimize the number of parallel operations fora load and to avoid size limitations, ensuring efficient and cost-effective data loading

 The pre-signed URL type allows users or applications to download or access files directly from a Snowflake stage without authentication. This URL type is open and can be used without needing to authenticate into Snowflake or pass an authorization token.

 In theInformation Schema and Account Usage, the column that identifies whether a view is secure or not is IS_SECURE2.

Snowflake uses a technique called pruning to limit the number of micro-partitions scanned by each query. Pruning effectively filters out unnecessary micro-partitions based on the query’s filter conditions, which can significantly improve query performance by reducing theamount of data scanned1.

 In Snowflake, schema objects include Pipes and File formats. Pipes are used for continuous data loading, and File formats specify the format of data files used in loading and unloading operations within Snowflake