SnowPro-Core Sample Questions Answers

 In Snowflake, a schema is a logical grouping of database objects, which can include streams and external tables. A stream is an object that allows users to query data that has changed in specified tables or views, and an external table is a table that references data stored outside of Snowflake. Roles, warehouses, users, and shares are not contained within a schema. References: SHOW OBJECTS, Database, Schema, & Share DDL

 By default, the Snowflake role required to create a share is ACCOUNTADMIN (D). This role has the necessary privileges to perform administrative tasks, including creating shares for data sharing purposes

In Snowflake, Streams are the objects that track Data Manipulation Language (DML) changes made to tables, such as inserts, updates, and deletes. Streams record these changes along with metadata about each change, enabling actions to be taken using the changed data. This process is known as change data capture (CDC)2.

 In Snowflake, you can share several types of objects with other Snowflake accounts. These include schemas, secure views, and secure user-defined functions (UDFs). Sharing these objects allows for collaboration and data access across different Snowflake accounts while maintaining security and governance controls4.

The search optimization service in Snowflake supports use cases involving conjunctions (AND) of multiple equality predicates. This service enhances the performance of queries that include multiple equality conditions by utilizing search indexes to quickly filter data without scanning entire tables or partitions. It's particularly beneficial for improving the response times of complex queries that rely on specific data matching across multiple conditions.

References:

• Snowflake Documentation: Search Optimization Service

When unloading data, the Parquet file format is known for its efficiency in preserving the data values for floating-point number columns. Parquet is a columnar storage file format that offers high compression ratios and efficient data encoding schemes. It is especially effective for floating-point data, as it maintains high precision and supports efficient querying and analysis.

References:

• Snowflake Documentation: Using the Parquet File Format for Unloading Data

Data masking policies in Snowflake allow for the obfuscation of specific data within a field, enabling some users to see the full data while limiting others. This feature is particularly useful for handling PII, ensuring that sensitive information is only visible to authorized users1.

 Snowpipe retains load history for 14 days. This allows users to view and audit the data that has been loaded into Snowflake using Snowpipe within this time frame3.

Scalar functions in Snowflake (and SQL in general) are designed to return a single value for each invocation. They operate on a single value and return a single result, making them suitable for a wide range of data transformations and calculations within queries.

References:

• Snowflake Documentation: Functions

• Purpose: The BUILD_STAGE_FILE_URL function generates a temporary, pre-signed URL that allows you to access a file within a Snowflake stage (internal or external). This URL requires authentication to use.
• Key Points:

• Snowflake Documentation (BUILD_STAGE_FILE_URL): https://docs.snowflake.com/en/sql-reference/functions/build_stage_file_url.html

When data is loaded into Snowflake, it undergoes a reorganization process where the data is stored in a columnar format and compressed. The columnar storage format enables efficient querying and data retrieval, as it allows for reading only the necessary columns for a query, thereby reducing IO operations. Additionally, Snowflake uses advanced compression techniques to minimize storage costs and improve performance. This combination of columnar storage and compression is key to Snowflake's data warehousing capabilities.

References:

• Snowflake Documentation: Data Storage and Organization

A Snowflake user would decide to use a materialized view instead of a regular view primarily when the base tables do not change frequently. Materialized views store the result of the view query and update it as the underlying data changes, making them ideal for situations where the data is relatively static and query performance is critical. By precomputing and storing the query results, materialized views can significantly reduce query execution times for complex aggregations, joins, and calculations.

References:

• Snowflake Documentation: Materialized Views

To insert JSON formatted string data into a VARIANT field in Snowflake, the correct function to use is PARSE_JSON. The PARSE_JSON function is specifically designed to interpret a JSON formatted string and convert it into a VARIANT type, which is Snowflake's flexible format for handling semi-structured data like JSON, XML, and Avro. This function is essential for loading and querying JSON data within Snowflake, allowing users to store and manage JSON data efficiently while preserving its structure for querying purposes. This function's usage and capabilities are detailed in the Snowflake documentation, providing users with guidance on how to handle semi-structured data effectively within their Snowflake environments.

References:

• Snowflake Documentation: PARSE_JSON

The replication feature in Snowflake provides several benefits, with disaster recovery and database failover and fallback being two of the primary advantages. Replication allows for the continuous copying of data from one Snowflake account to another, ensuring that a secondary copy of the data is available in case of outages or disasters. This capability supports disaster recovery strategies by allowing operations to quickly switch to the replicated data in a different account or region. Additionally, it facilitates database failover and fallback procedures, ensuring business continuity and minimizing downtime.

References:

• Snowflake Documentation: Data Replication

The LATERAL FLATTEN command in Snowflake produces a result set that includes several columns, among which PATH and INDEX are includedPATH indicates the path to the element within a data structure that needs to be flattened, and INDEX represents the index of the element if it is an array2.

A materialized view in Snowflake is a database object derived from a query specification, stored for later use, and can significantly speed up expensive aggregations on large data sets. Materialized views store the result of their underlying query, reducing the need to recompute the result each time the view is accessed. This makes them ideal for improving the performance of read-heavy, aggregate-intensive queries.

References:

• Snowflake Documentation: Using Materialized Views

The Search Optimization Service in Snowflake is designed to improve the performance of specific types of queries, particularly those involving extensive sets of WHERE conditions. By maintaining a search index on tables, this service can accelerate lookup and analytical queries, making it a valuable feature for optimizing query performance and reducing execution times for complex searches.

References:

• Snowflake Documentation: Search Optimization Service

By default, the ACCOUNTADMIN role in Snowflake has the ability to create a share from a shared database. This role has the highest level of access within a Snowflake account, including the management of all aspects of the account, such as users, roles, warehouses, and databases, as well as the creation and management of shares for secure data sharing with other Snowflake accounts.

References:

• Snowflake Documentation: Roles

 The Snowflake Cloud Services layer manages various services, including authentication and metadata management. This layer ties together all the different components of Snowflake to process user requests, manage sessions, and control access3.

Snowflake recommends file sizes between 100-250 MB compressed when loading data to optimize parallel processing. Smaller, compressed files can be loaded in parallel, which maximizes the efficiency of the virtual warehouses and speeds up the data loading process

The Query Profile in Snowflake provides a graphical representation and statistics for each component of the query's execution plan. This includes details such as the execution time, the number of rows processed, and the amount of data scanned for each operation within the query. The Query Profile is a crucial tool for understanding and optimizing the performance of queries, as it helps identify potential bottlenecks and inefficiencies.

References:

• Snowflake Documentation: Understanding the Query Profile

Snowflake's architecture is unique in that it combines elements of both traditional shared-disk and shared-nothing database architectures. This hybrid approach allows Snowflake to offer the scalability and performance benefits of a shared-nothing architecture (with compute and storage separated) while maintaining the simplicity and flexibility of a shared-disk architecture in managing data across all nodes in the system. This results in an architecture that provides on-demand scalability, both vertically and horizontally, without sacrificing performance or data cohesion.

References:

• Snowflake Documentation: Snowflake Architecture

The default file size when unloading data from Snowflake using the COPY command is not explicitly stated in the provided resources. However, Snowflake documentation suggests that the file size can be specified using the MAX_FILE_SIZE option in the COPY INTO  command2.

 Dynamic data masking is a feature in Snowflake that allows administrators to define masking policies to protect sensitive data. It enables partial visibility of the data to certain roles, such as functional managers, while hiding it from others, like end users

Snowflake supports the VARIANT and ARRAY data types for semi-structured data. VARIANT can store values of any other type, including OBJECT and ARRAY, making it suitable for semi-structured data formats like JSON. ARRAY is used to store an ordered list of elements

The Query Profile in Snowflake can identify common query problems, including:

• B. Inefficient pruning: This refers to the inability of a query to effectively limit the amount of data being scanned, potentially leading to suboptimal performance.
• D. Queries too large to fit in memory: This indicates that a query requires more memory than is available in the virtual warehouse, which can lead to spilling to disk and degraded performance.

The Query Profile helps diagnose these issues by providing detailed execution statistics and visualizations, aiding in query optimization and troubleshooting.

References:

• Snowflake Documentation: Query Profile

Top of Form

 In Snowflake, both materialized views and transient tables will incur storage charges because they store data. They will also incur compute charges when queries are run against them, as compute resources are used to process the queries. References: [COF-C02] SnowPro Core Certification Exam Study Guide

Snowpipe via REST API can reference both named internal stages within Snowflake and external stages, such as Amazon S3, Google Cloud Storage, or Microsoft Azure1. This means that Snowpipe is not limited to only external stages as a source for data loading.

References = [COF-C02] SnowPro Core Certification Exam Study Guide, Snowflake Documentation1

 Snowflake stored procedures can be created to execute with the privileges of the role that owns the procedure (owner’s rights) or with the privileges of the role that calls the procedure (caller’s rights). This allows for flexibility in managing security and access control within Snowflake1.

A materialized view in Snowflake denotes a pre-computed data set derived from a SELECT query specification and stored for later use. Unlike standard views, which dynamically compute the data each time the view is accessed, materialized views store the result of the query at the time it is executed, thereby speeding up access to the data, especially for expensive aggregations on large datasets.

References:

• Snowflake Documentation: Materialized Views

 The supported file formats for unloading data from Snowflake include JSON, Parquet, and CSV. These formats are commonly used for their flexibility and compatibility with various data processing tools

The responsibilities of Snowflake’s Cloud Service layer include authentication (A), which ensures secure access to the platform; resource management (B), which involves allocating and managing compute resources; and query parsing and optimization (D), which improves the efficiency and performance of SQL query execution3.

Characteristics of reader accounts in Snowflake include:

• A. Reader account users cannot add new data to the account: Reader accounts are intended for data consumption only. Users of these accounts can query and analyze the data shared with them but cannot upload or add new data to the account.
• E. Reader accounts enable data consumers to access and query data shared by the provider: One of the primary purposes of reader accounts is to allow data consumers to access and perform queries on the data shared by another Snowflake account, facilitating secure and controlled data sharing.

References:

• Snowflake Documentation: Reader Accounts

The SYSTEM$GET_PRIVATELINK function in Snowflake provides proxy information necessary for configuring PrivateLink connections, which can protect Snowsight as well as other Snowflake services. PrivateLink enhances security by allowing Snowflake to be accessed via a private connection within a cloud provider’s network, reducing exposure to the public internet.

References:

• Snowflake Documentation: PrivateLink Setup

The OBJECT_CONSTRUCT function in Snowflake is used to convert rows in a relational table into a single VARIANT column that represents each row as a JSON object. This function dynamically creates a JSON object from a list of key-value pairs, where each key is a column name and each value is the corresponding column value for a row. This is particularly useful for aggregating and transforming structured data into semi-structured JSON format for further processing or analysis.

References:

• Snowflake Documentation: Semi-structured Data Functions

In Snowflake, to extract a specific element from a JSON stored in a VARIANT column, the correct syntax is to use the dot notation. Therefore, the query select src.dealership from car_sales; will return the dealership information contained within each JSON object in the src column.

References: For a detailed explanation, please refer to the Snowflake documentation on querying semi-structured data.

In Snowflake, Cloud Services costs are incurred when the Cloud Services usage exceeds 10% of the compute usage (measured in credits). Therefore, scenarios A and E would result in Cloud Services charges because the Cloud Services usage is more than 10% of the compute credits used.

References:

• [COF-C02] SnowPro Core Certification Exam Study Guide
• Snowflake’s official documentation on billing and usage1

 The correct statement to accommodate the request for a marketing co-worker to change the size of their medium virtual warehouse called mktg__WH is to grant the MODIFY privilege on the warehouse to the ROLE MARKETING. This privilege allows the role to change the warehouse size among other properties.

References:

• [COF-C02] SnowPro Core Certification Exam Study Guide
• Snowflake Documentation on Access Control Privileges1

Snowflake’s Time Travel feature is used for both querying historical data in tables and restoring and cloning historical data in databases, schemas, and tables3. It allows users to access historical data within a defined period (1 day by default, up to 90 days for Snowflake Enterprise Edition) and is a key feature for data recovery and management. References: [COF-C02] SnowPro Core Certification Exam Study Guide

A clustering key can be defined when a table is created by appending a CLUSTER Where each clustering key consists of one or more table columns/expressions, which can be of any data type, except GEOGRAPHY, VARIANT, OBJECT, or ARRAY https://docs.snowflake.com/en/user-guide/tables-clustering-keys

The Snowflake Enterprise edition includes database replication and failover for business continuity and disaster recovery, as well as extended time travel capabilities for longer data retention periods1.

 Organizing files into logical paths can significantly improve the efficiency of data loading from an external stage. This practice helps in managing and locating files easily, which can be particularly beneficial when dealing with large datasets or complex directory structures1.

The PUT command is used to load data files into a Snowflake stage. This command uploads data files from a local file system to a specified stage in Snowflake

Tri-secret secure encryption is a security model employed by Snowflake that involves combining a customer-managed key with a Snowflake-managed key to create a composite key for encrypting data. This model enhances data security by requiring both the customer-managed key and the Snowflake-managed key to decrypt data, thus ensuring that neither party can access the data independently. It represents a balanced approach to key management, leveraging both customer control and Snowflake's managed services for robust data encryption.

References:

• Snowflake Documentation: Encryption and Key Management

 Protegrity is listed as a data tokenization integration partner for Snowflake. This partnership allows Snowflake users to utilize Protegrity’s tokenization solutions within the Snowflake environment3.

References = [COF-C02] SnowPro Core Certification Exam Study Guide, Snowflake Documentation

To temporarily bypass a network policy by configuring the user object property MINS_TO_BYPASS_NETWORK_POLICY, the USERADMIN role should be used. This role has the necessary privileges to modify user properties, including setting a temporary bypass for network policies, which can be crucial for enabling access under specific circumstances without permanently altering the network security configuration.

References:

• Snowflake Documentation: User Management

The SQL command used to delete files from a Snowflake internal stage is REMOVE. This command can be used to remove files from either an internal or external stage within Snowflake

When a Snowflake user increases the size of a suspended virtual warehouse, the changes to compute resources are queued but do not take immediate effect. The provisioning of additional compute resources occurs only when the warehouse is resumed. This ensures that resources are allocated efficiently, aligning with Snowflake's commitment to cost-effective and on-demand scalability.

References:

• Snowflake Documentation: Virtual Warehouses

 Materialized Views in Snowflake are designed to store the result of a query and can be refreshed to maintain up-to-date data. However, they have certain limitations, one of which is that they cannot be defined using a JOIN clause. This means that a Materialized View can only be created based on a single source table and cannot combine data from multiple tables using JOIN operations.

References:

• Snowflake Documentation on Materialized Views
• SnowPro® Core Certification Study Guide

The Enterprise edition of Snowflake allows for a dedicated metadata store, providing additional features designed for large-scale enterprises

The parse_json() function in Snowflake interprets an input string as a JSON document and produces a VARIANT value containing the JSON document. This function is specifically designed for parsing strings that contain valid JSON information3.

 In Snowflake’s access control model, the default owner of an object is the role that was used to create the object. This role has the OWNERSHIP privilege on the object and can grant access to other roles1

The query results cache can be used as long as the data in the table has not changed since the last time the query was run. If the underlying data has changed, Snowflake will not use the cached results and will re-execute the query1.

The minimum Snowflake edition required to use Dynamic Data Masking is the Enterprise edition. This feature is not available in the Standard edition2.

The auto-suspend and auto-resume settings in Snowflake apply to the entire virtual warehouse. These settings allow the warehouse to automatically suspend when it’s not in use, helping to save on compute costs. When queries or tasks are submitted to the warehouse, it can automatically resume operation. This functionality is designed to optimize resource usage and cost-efficiency.

References:

• SnowPro Core Certification Exam Study Guide (as of 2021)
• Snowflake documentation on virtual warehouses and their settings (as of 2021)

Data shares in Snowflake can be created and managed through the Snowflake web interface, which provides a user-friendly graphical interface for various operations. Additionally, SQL commands can be used to perform these tasks programmatically, offering flexibility and automation capabilities123.

The worksheet and database explorer feature in Snowsight allows users to tag frequently accessed worksheets for ease of access. This functionality helps users organize and quickly navigate to the worksheets they use most often, enhancing productivity and streamlining the data exploration and analysis process within Snowsight, Snowflake's web-based query and visualization interface.

References:

• Snowflake Documentation: Snowsight (UI for Snowflake)

The VARIANT data type in Snowflake is used to store JSON key-value pairs along with other semi-structured data formats like AVRO, BSON, and XML. The VARIANT data type allows for flexible and dynamic data structures within a single column, accommodating complex and nested data. This data type is crucial for handling semi-structured data in Snowflake, enabling users to perform SQL operations on JSON objects and arrays directly.

References:

• Snowflake Documentation: Semi-structured Data Types

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.

References:

• Snowflake Documentation: Query Performance Optimization

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.

Snowflake’s architecture is divided into three layers: database storage, query processing, and cloud services. The metadata, which includes information about the structure of the data, the SQL operations performed, and the service-level policies, is stored in the cloud services layer. This layer acts as the brain of the Snowflake environment, managing metadata, query optimization, and transaction coordination.

In Snowflake, to change the columns referenced in a view, the view must be recreated with the required changes. The ALTER VIEW command does not allow changing the definition of a view; it can only be used to rename a view, convert it to or from a secure view, or add, overwrite, or remove a comment for a view. Therefore, the correct approach is to drop the existing view and create a new one with the desired column references. 

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

When a database is cloned in Snowflake, it does not retain any privileges that were granted on the source object. The clone will need to have privileges reassigned as necessary for users to access it. References: [COF-C02] SnowPro Core Certification Exam Study Guide

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.

Efficient pruning in Snowflake is indicated by the number of partitions scanned out of the total available. If a small percentage of partitions are scanned, it suggests that the pruning process is effectively narrowing down the data, which can lead to improved query performance

The user property ‘MINS TO BYPASS MFA’ in Snowflake allows temporary bypass of MFA for a user, which can be set by an account administrator without contacting Snowflake Support2.

 To show all privileges granted to a specific schema, the command SHOW GRANTS ON SCHEMA  should be used3. In this case, it would be SHOW GRANTS ON SCHEMA ANALYTICS_DW.MARKETING. References: [COF-C02] SnowPro Core Certification Exam Study Guide

The OPERATE privilege is required for a role to resume a suspended warehouse if auto-resume is not enabled. This privilege allows the role to start, stop, suspend, or resume a virtual warehouse3.

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

Snowflake’s architecture allows for flexibility in account hosting across different cloud vendors and regions. This means that within a single organization, different Snowflake accounts can be set up in various cloud environments, such as AWS, Azure, or GCP, and in different geographical regions. This allows organizations to leverage the global infrastructure of multiple cloud providers and optimize their data storage and computing needs based on regional requirements, data sovereignty laws, and other considerations.

https://docs.snowflake.com/en/user-guide/intro-regions.html

 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

Snowflake credits are the unit of measure for the compute resources used in Snowflake. The number of credits consumed depends on the size of the virtual warehouse and the time it is running. Larger warehouses consume more credits per hour than smaller ones, and credits are billed for the time the warehouse is active, regardless of the actual usage within that time.

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

For data loading using Snowpipe, the recommended file size is a compressed file greater than 10 MB and up to 100 MB. This size range is optimal for Snowpipe’s continuous, micro-batch loading process, allowing for efficient and timely data ingestion without overwhelming the system with files that are too large or too small.

References:

• [COF-C02] SnowPro Core Certification Exam Study Guide
• Snowflake Documentation on Snowpipe1

 The size of the virtual warehouse for a task can be configured to handle concurrency automatically using a Multi-cluster warehouse (MCW). This is because tasks are designed to run their body on a schedule, and MCW allows for scaling compute resources to match the task’s execution needs without manual intervention. References: [COF-C02] SnowPro Core Certification Exam Study Guide

 User-level network policies in Snowflake can be created by roles with the necessary privileges to manage security and account settings. The ACCOUNTADMIN role has the highest level of privileges across the account, including the ability to manage network policies. The SECURITYADMIN role is specifically responsible for managing security objects within Snowflake, which includes the creation and management of network policies.

References:

• [COF-C02] SnowPro Core Certification Exam Study Guide
• Snowflake Documentation on Network Policies1
• Section 1.3 - SnowPro Core Certification Study Guide

To return results from the results cache in Snowflake, certain conditions must be met:

• Privileges: The user must have the appropriate privileges on the objects associated with the query. This ensures that only authorized users can access cached data.
• Time Frame: The query must have been run within 24 hours of the previously-run query. Snowflake’s results cache is designed to store the results of queries for a short period, typically 24 hours, to improve performance for repeated queries.

The cloud services layer of Snowflake architecture handles various aspects including security functions, authentication of user sessions, and access control, ensuring that only authorized users can access the data and services23.

 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.

 In Snowflake, a User-Defined Table Function (UDTF) can be accessed in the FROM clause of a query. UDTFs return a set of rows with one or more columns, which can be queried like a regular table

One of the security features of Snowflake includes the periodic rekeying of encrypted data, which is available with the Snowflake Enterprise edition and higher2. This ensures that the encryption keys are rotated regularly to maintain a high level of security. 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.

The Snowflake feature that allows for small volumes of data to be continuously loaded into Snowflake and incrementally made available for analysis is Snowpipe. Snowpipe is designed for near-real-time data loading, enabling data to be loaded as soon as it’s available in the storage layer3

Snowflake supports storing unstructured data and provides native support for semi-structured file formats such as JSON, Avro, Parquet, ORC, and XML1. GeoJSON, being a type of JSON, and XML are among the formats that can be stored in Snowflake. References: [COF-C02] SnowPro Core Certification Exam Study Guide

 In a Query Profile, the statistical information that indicates a query is too large to fit in memory includes bytes spilled to local cache and bytes spilled to local storage. These metrics suggest that the working data set of the query exceeded the memory available on the warehouse nodes, causing intermediate results to be written to disk

The WAIT_FOR_COMPLETION = TRUE parameter in an ALTER WAREHOUSE command ensures that the command does not return until the warehouse has completed resizing. This means that the command will wait until all the necessary compute resources have been provisioned and the warehouse size has been changed. References: [COF-C02] SnowPro Core Certification Exam Study Guide

The USERADMIN role in Snowflake has the ability to create and manage users and roles within the Snowflake environment. This role is specifically dedicated to user and role management and creation

With the create data EXCHANGE listing privilege, a Snowflake user can modify the properties of listings and submit them for approval or publishing on the Data Exchange. This allows them to manage and share data sets with consumers effectively. References: Based on general data exchange practices in cloud services as of 2021.

A scoped URL expires when the persisted query result period ends, which is typically after the results cache expires. This is currently set to 24 hours

The TABLE_STORAGE_METRICS view can be used to determine if a table has frequent row updates or deletes. This view provides detailed metrics on the storage utilization of tables within Snowflake, including metrics that reflect the impact of DML operations such as updates and deletes on table storage. For example, metrics related to the number of active and deleted rows can help identify tables that experience high levels of row modifications, indicating frequent updates or deletions.

References:

• Snowflake Documentation: TABLE_STORAGE_METRICS View

To extract the URL of a directory table on an external stage for further transformation in Snowflake, the GET_ABSOLUTE_PATH function can be used. This function returns the full path of a file or directory within a specified stage, enabling users to dynamically construct URLs for accessing or processing data stored in external stages.

References:

• Snowflake Documentation: Working with Stages

Transient tables in Snowflake are designed for temporary or intermediate workloads with the following characteristics:

• B. Transient tables can be cloned to permanent tables: This feature allows users to create copies of transient tables for permanent use, providing flexibility in managing data lifecycles.
• C. Transient tables persist until they are explicitly dropped: Unlike temporary tables that exist for the duration of a session, transient tables remain in the database until explicitly removed by a user, offering more durability for short-term data storage needs.

References:

• Snowflake Documentation: Transient Tables

The REVOKE ROLE command is used to remove a role from another role or a user in Snowflake. This command is part of Snowflake's role-based access control system, allowing administrators to manage permissions and access to database objects efficiently by adding or removing roles from users or other roles.

References:

• Snowflake Documentation: REVOKE ROLE

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 Cloud Services layer in Snowflake is responsible for various services, including security (like authentication and authorization) and metadata management (like query parsing and optimization). References: Based on general cloud architecture knowledge as of 2021.

 Snowflake provides Multi-Factor Authentication (MFA) support as an integrated feature, powered by the Duo Security service. This service is managed completely by Snowflake, and users do not need to sign up separately with Duo1

Snowflake’s documentation recommends producing the largest files possible for data loading, as larger files reduce the number of files to process and the overhead associated with handling many small files. This approach can maximize the load performance by leveraging Snowflake’s ability to ingest large files efficiently1. References: [COF-C02] SnowPro Core Certification Exam Study Guide

A characteristic of a materialized view is that the data accessed through it can be stale. This is because the data in a materialized view may not reflect the latest changes in the base tables until the view is refreshed

The Activity area of Snowsight includes the Query History page, which allows users to monitor and view details about queries executed in their account, including performance data1. It also includes the Automatic Clustering History, which provides insights into the automatic clustering operations performed on tables2.

 For the ALLOWED VALUES tag property, the maximum number of possible string values for a single tag is 256. This allows for a wide range of values to be assigned to a tag when it is set on an object

To ensure a data consumer has access to the required objects, a data provider can enable the data sharing feature and validate that the consumer can access the views or tables shared with them. References: Based on general data sharing practices in cloud services as of 2021.

When a virtual warehouse in Snowflake is resized, specifically when it is increased in size, the additional compute resources become immediately available to all running and queued queries. This means that the performance of these queries can improve due to the increased resources. Conversely, when the size of a warehouse is reduced, the compute resources are not removed until they are no longer being used by any current operations1.

References:

• [COF-C02] SnowPro Core Certification Exam Study Guide
• Snowflake Documentation on Virtual Warehouses2

The Snowflake storage layer is responsible for storing data in an optimized, compressed, columnar format. This includes micro-partitions, which are the fundamental storage units that contain the actual data stored in Snowflake. Additionally, persisted query results, which are the results of queries that have been materialized and stored for future use, are also kept within this layer. This design allows for efficient data retrieval and management within the Snowflake architecture1.

References:

• [COF-C02] SnowPro Core Certification Exam Study Guide
• Key Concepts & Architecture | Snowflake Documentation2

 In Snowflake, when the account is located on Microsoft Azure, a valid source for an external stage can be an Azure container or a folder path within an Azure container. This includes Azure Blob storage which is accessible via the azure:// endpoint. A Windows server file share on Azure, if configured properly, can be a valid source for staging data files for Snowflake. Options A, B, and C are not supported as direct sources for an external stage in Snowflake on Azure12. References: [COF-C02] SnowPro Core Certification Exam Study Guide

The COPY command in Snowflake allows for the reordering of columns as they are loaded into a table, and it also permits the omission of columns from the source file during the load process. This provides flexibility in handling the schema of the data being ingested. References: [COF-C02] SnowPro Core Certification Exam Study Guide

Snowflake’s Continuous Data Protection (CDP) encompasses a set of features that help protect data stored in Snowflake against human error, malicious acts, and software failure. Time Travel allows users to access historical data (i.e., data that has been changed or deleted) for a defined period, enabling querying and restoring of data. Fail-safe is an additional layer of data protection that provides a recovery option in the event of significant data loss or corruption, which can only be performed by Snowflake.

References:

• Continuous Data Protection | Snowflake Documentation1
• Data Storage Considerations | Snowflake Documentation2
• Snowflake SnowPro Core Certification Study Guide3
• Snowflake Data Cloud Glossary

https://docs.snowflake.com/en/user-guide/data-availability.html

The parameter STATEMENT_QUEUED_TIMEOUT_IN_SECONDS sets the limit for a query to wait in the queue in order to get its chance of running on the warehouse. The query will quit after reaching this limit. By default, the value of this parameter is 0 which mean the queries will wait indefinitely in the waiting queue

https://community.snowflake.com/s/article/Warehouse-Concurrency-and-Statement-Timeout-Parameters#:~:text=The%20parameter%20STATEMENT_QUEUED_TIMEOUT_IN_SECONDS%20sets%20the,indefinitely%20in%20the%20waiting%20queue .

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

The purpose of an External Function in Snowflake is to call code that executes outside of the Snowflake environment. This allows Snowflake to interact with external services and leverage functionalities that are not natively available within Snowflake, such as calling APIs or running custom code hosted on cloud services3.

https://docs.snowflake.com/en/sql-reference/external-functions.html

 Snowflake’s architecture allows for the use of a query result cache that stores the results of queries for a period of time. If the same query is run again and the underlying data has not changed, Snowflake can retrieve the result from this cache without needing to re-run the query on an active warehouse, thus saving on compute resources.

 Snowflake manages various compute resources and features, including Snowpipe and the ability to scale up a warehouse. Snowpipe is Snowflake’s continuous data ingestion service that allows users to load data as soon as it becomes available. Scaling up a warehouse refers to increasing the compute resources allocated to a virtual warehouse to handle larger workloads or improve performance.

References:

• [COF-C02] SnowPro Core Certification Exam Study Guide
• Snowflake Documentation on Snowpipe and Virtual Warehouses1

The Information Schema and Account Usage Share in Snowflake provide metadata and historical usage data for various objects within a Snowflake account. Specifically, they offer storage information for Tables, Databases, and Internal Stages. These schemas contain views and table functions that allow users to query object metadata and usage metrics, such as the amount of data stored and historical activity.

• Tables: The storage information includes data on the daily average amount of data in database tables.
• Databases: For databases, the storage usage is calculated based on all the data contained within the database, including tables and stages.
• Internal Stages: Internal stages are locations within Snowflake for temporarily storing data, and their storage usage is also tracked.

References: The information is verified according to the SnowPro Core Certification Study Guide and Snowflake documentation

In Snowflake, to create a materialized view, the user must have the necessary privileges on the schema where the view will be created. These privileges are granted through roles, not directly to individual users. Therefore, the correct process is to grant the role to the user and then grant the privilege to create the materialized view to the role itself.

The statement GRANT ROLE MYROLE TO USER USER1; grants the specified role to the user, allowing them to assume that role and exercise its privileges. The subsequent statement CREATE MATERIALIZED VIEW ON SCHEMA MYDB.MYSCHEMA TO MYROLE; grants the privilege to create a materialized view within the specified schema to the role MYROLE. Any user who has been granted MYROLE can then create materialized views in MYDB.MYSCHEMA.

References:

• Snowflake Documentation on Roles
• Snowflake Documentation on Materialized Views

 In Snowflake, a reader account is a type of account that is intended for consuming shared data rather than performing any data management or DDL operations. The CREATE SHARE command is used to share data from your account with another account, which is not a capability provided to reader accounts. Reader accounts are typically restricted from creating shares, as their primary purpose is to read shared data rather than to share it themselves.

References:

• Snowflake Documentation on Reader Accounts
• SnowPro® Core Certification Study Guide

Semi-structured

JSON, Parquet

Snowflake supports unloading data in several semi-structured file formats, including Parquet and JSON. These formats allow for efficient storage and querying of semi-structured data, which can be loaded directly into Snowflake tables without requiring a predefined schema12.

https://docs.snowflake.com/en/user-guide/data-unload-prepare.html#:~:text=Supported%20File%20Formats,-The%20following%20file &text=Delimited%20(CSV%2C%20TSV%2C%20etc.)

 Snowflake applies egress charges in the case of database replication when data is transferred out of a Snowflake region to another region or cloud provider. This is because the data transfer incurs costs associated with moving data across different networks. Egress charges are not applied for data sharing within the same region, query result retrieval, or loading data into Snowflake, as these actions do not involve data transfer across regions.

References:

• [COF-C02] SnowPro Core Certification Exam Study Guide
• Snowflake Documentation on Data Replication and Egress Charges1

 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

In Snowflake, a Pipe is the object designed to enable the continuous, near-real-time loading of data from files as soon as they are available in a cloud storage location. Pipes use Snowflake’s COPY command to load data and can be associated with a Stage object to monitor for new files. When new data files appear in the stage, the pipe automatically loads the data into the target table.

References:

• Snowflake Documentation on Pipes
• SnowPro® Core Certification Study Guide

https://docs.snowflake.com/en/user-guide/data-load-snowpipe-intro.html

Temporary tables in Snowflake do not consume storage costs. They are designed for transient data that is needed only for the duration of a session. Data stored in temporary tables is held in the virtual warehouse's cache and does not persist beyond the session's lifetime, thereby not incurring any storage charges.

References:

• Snowflake Documentation: Temporary Tables

The Fail-safe retention period for transient and temporary tables in Snowflake is 0 days. Fail-safe is a feature designed to protect data against accidental loss or deletion by retaining historical data for a period after its Time Travel retention period expires. However, transient and temporary tables, which are designed for temporary or short-term storage and operations, do not have a Fail-safe period. Once the data is deleted or the table is dropped, it cannot be recovered.

References:

• Snowflake Documentation: Understanding Fail-safe

 To ensure that additional multi-clusters are resumed with no delay, a virtual warehouse should be configured to a size larger than generally required. This configuration allows for immediate availability of additional resources when needed, without waiting for new clusters to start up

 In an auto-scaling multi-cluster virtual warehouse with the SCALING_POLICY set to ECONOMY, another cluster is started when the system has enough load for 2 minutes (A). This policy is designed to optimize the balance between performance and cost, starting additional clusters only when the sustained load justifies it2.

 To traverse semi-structured data in Snowflake, a user can insert a colon (:) between the VARIANT column name and any first-level element. This path syntax is used to retrieve elements in a VARIANT column4.

 When the DROP MANAGED ACCOUNT command is executed in Snowflake, it removes the managed account, including all objects created within the account, and access to the account is immediately restricted2.

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

Dynamic Data Masking in Snowflake supports tables and views. These objects can have masking policies applied to their columns to dynamically mask data at query time3.

 A user with the OWNERSHIP privilege on a user object or the CREATE USER privilege on the account can create or manage other users in a Snowflake account56.

The TABLE_STORAGE_METRICS metadata table stores the storage utilization information, including for tables that have been dropped but are still incurring storage costs2.

The FLATTEN function can be used with the recursive argument to return a list of distinct key names in all nested elements within an object. This function is particularly useful for working with semi-structured data in Snowflake

The query acceleration service in Snowflake is designed to benefit queries that involve large scans and selective filters. This service can offload portions of the query processing work to shared compute resources, which can handle these types of workloads more efficiently by performing more work in parallel and reducing the wall-clock time spent in scanning and filtering2. References: [COF-C02] SnowPro Core Certification Exam Study Guide

The ACCESS_HISTORY view in Snowflake is utilized to support compliance auditing. It provides detailed information on data access within Snowflake, including reads and writes by user queries. This view is essential for regulatory compliance auditing as it offers insights into the usage of tables and columns, and maintains a direct link between the user, the query, and the accessed data1.

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

 To validate data unloaded using the COPY INTO command, a Snowflake user can use the VALIDATION_MODE parameter within the SQL statement to test the files for errors without loading them3.

Multi-Factor Authentication (MFA) provides increased login security for users connecting to Snowflake. Snowflake’s MFA is powered by Duo Security service, which adds an additional layer of security during the login process.

A Stream object in Snowflake is used for change data capture (CDC), which records data manipulation language (DML) changes made to tables, including inserts, updates, and deletes3.

A directory table in Snowflake is used to store file-level metadata about the data files in a stage. It is conceptually similar to an external table and provides information such as file size, last modified timestamp, and file URL. References: [COF-C02] SnowPro Core Certification Exam Study Guide

Unstructured data stored in Snowflake can be retrieved by using SQL functions to generate URLs that point to the data. These URLs can then be used to download the data directly to a client

The RETURN_ERRORS value in the VALIDATION_MODE option of the COPY command instructs Snowflake to validate the data files and return errors encountered across all specified files, including those that were partially loaded during an earlier load2. References: [COF-C02] SnowPro Core Certification Exam Study Guide

In owner’s rights stored procedures, certain commands are restricted to maintain security and integrity. The SHOW and DESCRIBE commands are limited because they can reveal metadata and structure information that may not be intended for all roles. 

The LIST and PUT commands are specific to SnowSQL and cannot be executed in the web interface or other SQL clients. LIST is used to display the contents of a stage, and PUT is used to upload files to a stage. References: [COF-C02] SnowPro Core Certification Exam Study Guide

The STRIP NULL_VALUES file format option, when set to TRUE, removes object or array elements that contain null values during the loading process of semi-structured data files into Snowflake. This ensures that the data loaded into Snowflake tables does not contain these null elements, which can be useful when the “null” values in files indicate missing values and have no other special meaning2.

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

Snowflake’s architecture allows for the independent scaling of compute resources, meaning you can increase or decrease the computational power as needed without affecting storage. This separation also means that storage can grow independently of compute usage, allowing for more flexible and cost-effective data management. 

 The factors that impact storage costs in Snowflake include the account type (Capacity or On Demand) and the cloud region used by the account. These factors determine the rate at which storage is billed, with different regions potentially having different rates3.

The purpose of a Query Profile is to provide a detailed analysis of a particular query’s execution plan, including the mechanics, behavior, and performance. It helps in identifying potential performance bottlenecks and areas for optimization

 In Snowflake, a user with the SECURITYADMIN role or higher can activate and enforce a network policy for all users in an account. Additionally, a role that has ownership of the network policy can also activate and enforce it

When federated authentication is activated in Snowflake, users authenticate via an external identity provider (IdP) rather than using Snowflake-managed credentials. Therefore, a user with a password defined by Snowflake will be unable to enter a password and must use their IdP credentials to log in.

QUSTION NO: 579

What value provides information about disk usage for operations where intermediate results do not fit in memory in a Query Profile?

A. IO

B. Network

C. Pruning

D. Spilling

Answer: D

In Snowflake, when a query execution requires more memory than what is available, Snowflake handles these situations by spilling the intermediate results to disk. This process is known as "spilling." The Query Profile in Snowflake includes a metric that helps users identify when and how much data spilling occurs during the execution of a query. This information is crucial for optimizing queries as excessive spilling can significantly slow down query performance. The value that provides this information about disk usage due to intermediate results not fitting in memory is appropriately labeled as "Spilling" in the Query Profile.

References:

• Snowflake Documentation on Query Profile and Performance: This section explains the various components of the query profile, including the spilling metric, which indicates disk usage for operations where intermediate results exceed available memory.

SnowCD is a connectivity diagnostic tool that helps users troubleshoot network connections to Snowflake. It performs a series of checks to evaluate the network connection and provides suggestions for resolving any issues4.

To determine which user has accessed a database object containing sensitive information, a Snowflake administrator can query the ACCESS_HISTORY view in the ACCOUNT_USAGE schema, which provides information about access to database objects3.

Running a virtual warehouse is required when loading data into a table and when unloading data from a table because these operations require compute resources that are provided by the virtual warehouse23.

 A Query Profile provides detailed execution information for a query, which can be used to analyze the performance and behavior of queries. This information can help users optimize and right-size their virtual warehouses for better efficiency. References: [COF-C02] SnowPro Core Certification Exam Study Guide

The parameter DATA_RETENTION_TIME_IN_DAYS can be set at the account level to define the minimum number of days Snowflake retains historical data for Time Travel1.

Snowflake stores metadata for rows in micro-partitions, including the range of values for each column and the number of distinct values1.

When using the ALLOW_CLIENT_MFA_CACHING parameter, a cached Multi-Factor Authentication (MFA) token is valid for up to 4 hours. This allows for continuous, secure connectivity without users needing to respond to an MFA prompt at the start of each connection attempt to Snowflake within this timeframe2.

The Snowflake command to unload the result of a query to a single file is COPY INTO with SINGLE = TRUE followed by a GET command to download the file. This command unloads the query result into a single file in the specified internal stage

 Snowflake supports the storage of semi-structured data using the ARRAY and VARIANT data types. The ARRAY data type can directly contain VARIANT, and thus indirectly contain any other data type, including itself. The VARIANT data type can store a value of any other type, including OBJECT and ARRAY, and is often used to represent semi-structured data formats like JSON, Avro, ORC, Parquet, or XML34.

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

The ACCESS_HISTORY view in Snowflake is a powerful tool for enhancing data governance, especially concerning monitoring and auditing data access patterns for both read and write operations. The key ways in which ACCESS_HISTORY enhances overall data governance are:

• B. Provides a unified picture of what data was accessed and when it was accessed: This view logs details about query executions, including the objects (tables, views) accessed and the timestamps of these accesses. It's instrumental in auditing and compliance scenarios, where understanding the access patterns to sensitive data is critical.
• E. Determines whether a given row in a table can be accessed by the user by filtering the data based on a given policy: While this option is a bit of a misinterpretation of what ACCESS_HISTORY directly offers, it indirectly supports data governance by providing the information necessary to analyze access patterns. This analysis can then inform policy decisions, such as implementing Row-Level Security (RLS) to restrict access to specific rows based on user roles or attributes.

ACCESS_HISTORY does not automatically apply data masking or tag columns with personal information. However, the insights derived from analyzing ACCESS_HISTORY can be used to identify sensitive data and inform the application of masking policies or other security measures.

References:

• Snowflake Documentation on ACCESS_HISTORY: Access History

Temporary and transient tables in Snowflake share several characteristics, notably, neither table type has a Fail-safe period. Fail-safe is a feature that provides additional data protection beyond the Time Travel period. However, this feature does not apply to temporary or transient tables. Additionally, for both types of tables, the data retention period effectively ends when the tables are dropped. This means that once these tables are deleted, their data is not recoverable, distinguishing them from permanent tables, which benefit from Snowflake's Time Travel and Fail-safe features.References: Snowflake Documentation on Table Types