Snowflake COF-C02 - SnowPro Core Certification Exam

Snowflake supports reader accounts, which are a type of account that allows data providers to share data with consumers who are not Snowflake customers. However, for data sharing to occur, the consumer needs to become a licensed Snowflake customer because data sharing is only supported between Snowflake accounts. References: Introduction to Secure Data Sharing | Snowflake Documentation2.

The semi-structured data function that interprets an input string as a JSON document and produces a VARIANT value is PARSE_JSON. This function is used to parse a JSON formatted string and return it as a VARIANT data type, which can then beused for further processing within Snowflake3.

In Snowflake, a tabular User-Defined Function (UDF) is defined with a return clause that includes the keyword “TABLE.” This indicates that the UDF will return a set of rows, which can be used in the FROM clause of a query. References: Based on my internal knowledge as of 2021.

To find out which numeric values are present in both tables, the INTERSECT set operator should be used. This operator returns rows from one query’s result set which also appear in another query’s result set, effectively finding the common elements between the two tables45.

 Snowpark is designed to bring the data programmability to Snowflake, enabling developers to write code in familiar languages like Scala, Java, and Python. It allows for the execution of these codes directly within Snowflake’s virtual warehouses, eliminating the need for a separate cluster. Additionally, Snowpark’s compatibility with Spark allows users to leverage their existing Spark code with minimal changes1.

Snowflake’s search optimization service supports tables and views that are not protected by row access policies. It is designed to improve the performance of certain types of queries on tables, including selective point lookup queries and queries on fields in VARIANT, OBJECT, and ARRAY (semi-structured) columns1.

 The VALIDATION_MODE parameter can be used with the COPY command to verify data files without loading them into the specified table. This parameter allows users to check for errors in the files

 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.

Snowflake integrates Duo Security to support Multi-Factor Authentication (MFA). This feature provides increased login security for users connecting to Snowflake, and it is managed completely by Snowflake without the need for users to sign up separately with Duo4.

 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

 The OBJECT_CONSTRUCT function is used with the COPY INTO command to convert the rows in a relational table to a single VARIANT column, which can then be unloaded into a file. This is useful for transforming table data into a semi-structured JSON format

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.

The bulk data load history available after a COPY statement is stored in the metadata of the pipe and is retained for 64 days1.

 Snowflake recommends using the COPY command for bulk loading data batches from files already available in cloud storage. This command allows for efficient and large-scale data loading operations from files staged in cloud storage into Snowflake tables3.

To provide a user with the necessary access to create a materialized view in a schema, the user must be granted a role that has the CREATE MATERIALIZED VIEW privilege on that schema. First, the role is granted to the user, and then the privilege is granted to the role

 Clustering in Snowflake refers to the organization of data within micro-partitions, which are contiguous units of storage within Snowflake tables. Clustering keys can be defined to co-locate similar rows in the same micro-partitions, improving scan efficiency and query performance12.

 Snowflake’s billing for virtual warehouses is per-second, with a minimum of 60 seconds for each time the warehouse is started or resumed. Therefore, if a warehouse runs for 61 seconds, it is billed for 61 seconds. If it is then shut down and restarted, running for anadditional 30 seconds, it is billed for another 60 seconds (the minimum charge for a restart), totaling 121 seconds2

The Snowpark API allows developers to create User-Defined Functions (UDFs) in various languages, including Python, which is known for its ease of use and wide adoption in data-related tasks. References: Based on general programming and cloud data service knowledge as of 2021.

The first user assigned to a new Snowflake account, typically with the ACCOUNTADMIN role, should create at least one additional user with the USERADMIN administrative privilege. This role is responsible for creating and managing users and roles within the Snowflake account. References: Access control considerations | Snowflake Documentation