COF-C02 Questions and Answers

The purpose of the Snowflake SPLIT_TO_TABLE function is to split a string based on a specified delimiter and flatten the results into rows. This table function is useful for transforming a delimited string into a set of rows that can be further processed or queried5.

 Storing JSON data in a table with a VARIANT data type is optimal for querying because it allows Snowflake to leverage its semi-structured data capabilities. This approach enables efficient storage and querying without the need for flattening the data, which can be performance-intensive1.

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

 A masking policy in Snowflake consists of a single data type, with one or more conditions, and one or more masking functions. These components define how the data is masked based on the specified conditions3.

 Once an internal stage is dropped in Snowflake, it cannot be recovered or restored using Time Travel or UNDROP commands. The only option is to recreate the dropped stage

 A Scoped URL permits temporary access to a staged file without the need to grant privileges to the stage or to issue access tokens. It provides a secure way to share access to files stored in Snowflake

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

Snowflake bills virtual warehouse usage in one-minute increments, rounding up to the nearest minute for any partial minute of compute time used. If a virtual warehouse runs for 61 seconds and then, after being shut down, restarts and runs for an additional 30 seconds, the total time billed would be 120 seconds or 2 minutes. The first 61 seconds are rounded up to 2 minutes, and the subsequent 30 seconds are within a new minute, which is also rounded up to the nearest minute.

References:

Snowflake Documentation: Virtual Warehouses Billing

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

Valid sub-clauses to the OVER clause for a window function in SQL are:

C. ORDER BY: This clause specifies the order in which the rows in a partition are processed by the window function. It is essential for functions that depend on the row order, such as ranking functions.

D. PARTITION BY: This clause divides the result set into partitions to which the window function is applied. Each partition is processed independently of other partitions, making it crucial for functions that compute values across sets of rows that share common characteristics.

These clauses are fundamental to defining the scope and order of data over which the window function operates, enabling complex analytical computations within SQL queries.

References:

Snowflake Documentation: Window Functions

When creating a CSV file format in Snowflake and the requirement is to wrap columns by single quotes or double quotes, the FIELD_OPTIONALLY_ENCLOSED_BY parameter should be used in the file format specification. This parameter allows you to define a character (either a single quote or a double quote) that can optionally enclose each field in the CSV file, providing flexibility in handling fields that contain special characters or delimiters as part of their data.

References:

Snowflake Documentation: CSV File Format

To access a file URL from an external stage in Snowflake, the minimum permission required is USAGE on the stage object. USAGE permission allows a user to reference the stage in SQL commands, necessary for actions like listing files or loading data from the stage, but does not permit the user to alter or drop the stage.

References:

Snowflake Documentation: Access Control

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

To utilize the search optimization service in Snowflake, the correct syntax for granting privileges to a role involves specific commands that include adding search optimization capabilities:

Option C: GRANT ADD SEARCH OPTIMIZATION ON SCHEMA TO ROLE . This command grants the specified role the ability to implement search optimization at the schema level, which is essential for enhancing search capabilities within that schema.

Options A and B do not include the correct verb "ADD," which is necessary for this specific type of grant command in Snowflake. Option D incorrectly mentions the database level, as search optimization privileges are typically configured at the schema level, not the database level.References: Snowflake documentation on the use of GRANT statements for configuring search optimization.

The Access_History view provides detailed metadata about how objects in Snowflake are accessed and used.

Key benefits include:

Tracking sensitive data movement (D): Ensures compliance with regulations by providing visibility into data usage.

Tracking relationships among objects (E): Helps understand dependencies, such as which queries access specific tables or views.

References:

Snowflake Documentation: ACCESS_HISTORY View

Data Governance in Snowflake

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

To start configuring Snowflake for Single Sign-On (SSO), the CREATE SECURITY INTEGRATION command is used. This command sets up a security integration object in Snowflake, which is necessary for enabling SSO with external identity providers using SAML 2.01.

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

SnowSQL, Snowflake's command-line client, can be used to diagnose and troubleshoot network connections. SnowSQL provides various commands and options to test connectivity, configure network settings, and troubleshoot issues related to network connections between the client and Snowflake.

References:

Snowflake Documentation: SnowSQL

The SYSTEM$IS_LISTING_PURCHASED function is used in Snowflake's Data Marketplace to check if a user has purchased access to a shared data listing.

This can be combined with access control logic to display specific data only to paying customers.

Why Other Options Are Incorrect:

A. SYSTEM$ALLOWLIST: No such system function exists.

B. SYSTEM$ALLOWLIST_PRIVATELINK: Used for managing network access via PrivateLink, not for data shares.

C. SYSTEM$AUTHORIZE_PRIVATELINK: Authorizes PrivateLink connections, unrelated to data sharing.

References:

Snowflake Data Sharing Functions

In Snowflake streams, the METADATASACTION column indicates the type of data manipulation operation that has occurred. The possible values include INSERT and DELETE.

INSERT: Indicates that a new row has been inserted into the table.

DELETE: Indicates that a row has been deleted from the table.

References:

Snowflake Documentation: Change Data Capture (CDC) with Streams

Snowflake Documentation: Stream Data Capture

When accessing unstructured data files in Snowflake, the HTTPS URL identifies the database, schema, stage, and file path.

Example:

https:// .snowflakecomputing.com////

References:

Snowflake Documentation: Managing Unstructured Data

In Snowflake, permissions for accessing database objects, including tables, are not granted directly to users but rather to roles. A role encapsulates a collection of privileges on various Snowflake objects. Users are then granted roles, and through those roles, they inherit the permissions necessary to read a table or perform other actions. This approach adheres to the principle of least privilege, allowing for granular control over database access and simplifying the management of user permissions.

Masking policies in Snowflake require a minimum of the Business Critical Edition.

This feature enables dynamic masking of plain-text data at query time to meet compliance and security requirements.

Example:

sql

CopyEdit

CREATE MASKING POLICY ssn_mask AS (val STRING)

RETURNS STRING ->

CASE

WHEN CURRENT_ROLE() IN ('DATA_ANALYST') THEN '***-**-****'

ELSE val

END;

References:

Snowflake Documentation: Dynamic Data Masking

Snowflake Editions Comparison

The Snowflake feature that helps troubleshoot issues in SQL query expressions and commonly identify performance bottlenecks is the Query Profile. The Query Profile provides a detailed breakdown of a query's execution plan, including each operation's time and resources consumed. It visualizes the steps involved in the query execution, highlighting areas that may be causing inefficiencies, such as full table scans, large joins, or operations that could benefit from optimization.

By examining the Query Profile, developers and database administrators can identify and troubleshoot performance issues, optimize query structures, and make informed decisions about potential schema or indexing changes to improve performance.

References:

Snowflake Documentation on Query Profile: Using the Query Profile

The search optimization service in Snowflake enhances query performance by maintaining a persistent data structure. This structure indexes the values of table columns across micro-partitions, allowing Snowflake to quickly identify which micro-partitions contain relevant data for a query. By efficiently narrowing down the search space, this service reduces the amount of data scanned during query execution, leading to faster response times and more efficient use of resources.References: Snowflake Documentation on Search Optimization Service

The minimum Snowflake edition that supports database replication is the Enterprise edition. Database replication allows data to be replicated between different Snowflake accounts or regions, providing high availability and disaster recovery capabilities.

References:

Snowflake Documentation: Database Replication

When a query containing a WHERE clause is running longer than expected, and the Query Profile shows that all micro-partitions are being scanned, the query can be optimized by adding a clustering key to the table.

Understanding Micro-Partitioning in Snowflake:

Snowflake automatically partitions tables into micro-partitions for efficient storage and query performance.

Each micro-partition contains metadata about the range of values it holds, which helps in pruning irrelevant partitions during query execution.

Role of Clustering Keys:

A clustering key defines how data in a table is organized within micro-partitions.

By specifying a clustering key, you can control the physical layout of data, ensuring that related rows are stored together.

This organization improves query performance by reducing the number of micro-partitions that need to be scanned.

Optimizing Queries with Clustering Keys:

Adding a clustering key based on columns frequently used in WHERE clauses helps Snowflake quickly locate and scan relevant micro-partitions.

This minimizes the amount of data scanned and reduces query execution time.

Example:

ALTER TABLE my_table CLUSTER BY (column1, column2);

This command adds a clustering key to my_table using column1 and column2.

Future queries that filter on these columns will benefit from improved performance.

Benefits:

Reduced query execution time: Fewer micro-partitions need to be scanned.

Improved resource utilization: More efficient data retrieval leads to lower compute costs.

References:

Snowflake Documentation: Clustering Keys

Snowflake Documentation: Query Profile

The LOOP type of loop in Snowflake Scripting does not have a built-in termination condition and requires a BREAK statement to stop executing4.

The Notify & Suspend action for a resource monitor in Snowflake sends a notification to all account administrators who have notifications enabled and suspends all assigned warehouses. However, the suspension only occurs after all currently running statements in the warehouses have been completed1. References: [COF-C02] SnowPro Core Certification Exam Study Guide

The ACCOUNTADMIN role in Snowflake has the highest level of privileges, including the ability to manage accounts, users, roles, and all objects within the account. This role is specifically granted the permission to rename an account and specify whether the original URL can be used to access the renamed account. The ACCOUNTADMIN role encompasses broad administrative capabilities, ensuring that users assigned this role can perform critical account management tasks.References: Snowflake Documentation on Roles and Permissions

Excessive spillage in the Query Profile indicates that intermediate query results are being written to remote storage (disk) instead of being processed in memory. This usually happens when:

The virtual warehouse does not have sufficient resources (e.g., memory, compute power).

Large datasets or complex operations (e.g., joins, aggregations) require more memory than available.

Solution:

Increase the size of the virtual warehouse to provide more compute and memory resources.

Why Other Options Are Incorrect:

A. Poor query optimization: This could contribute, but spillage is primarily tied to resource constraints.

B. Expired temporary tables: Temporary tables have no relation to spillage.

D. Improper CTEs: The use of CTEs does not directly cause spillage.

References:

Query Profile and Performance

Setting MAX_CLUSTER_COUNT defines the maximum number of clusters for a multi-cluster virtual warehouse.

To handle increased concurrency without over-provisioning resources or enabling auto-scaling:

Set MIN_CLUSTER_COUNT and MAX_CLUSTER_COUNT to fixed values (e.g., MAX_CLUSTER_COUNT = 10).

This ensures resource usage is controlled and auto-scaling is avoided.

Why Other Options Are Incorrect:

A. WAREHOUSE_SIZE = LARGE: Does not control concurrency or prevent auto-scaling.

B. WAREHOUSE_TYPE = SNOWPARK-OPTIMIZED: Designed for ML workloads, unrelated to concurrency control.

D. ENABLE_QUERY_ACCELERATION = TRUE: Increases compute power dynamically but does not address concurrency.

References:

Multi-Cluster Warehouses

Snowflake network policies are a security feature that allows administrators to control access to Snowflake by specifying allowed and blocked IP address ranges. These policies apply to all editions of Snowflake, making them widely applicable across different Snowflake environments. They are specifically designed to restrict or enable access based on the originating IP addresses of client requests, adding an extra layer of security.

Network policies are not applied to roles but are set at the account or user level. They are not activated using ALTER DATABASE SQL commands but are managed through ALTER ACCOUNT or ALTER NETWORK POLICY commands. The management of network policies does not exclusively require the ORGADMIN role; instead, they can be managed by users with the necessary privileges on the account.

A. Storage Costs: Different Snowflake editions have varying unit costs for storage. For example, Business Critical edition typically incurs higher costs compared to the Standard edition.

C. Compute Credits: The cost of compute credits also varies across editions, with higher editions offering more advanced features at a premium cost.

References:

Snowflake Documentation: Editions Overview

Snowflake Pricing Model

Alerts in Snowflake are schema-level objects that allow users to define conditions and actions to be performed automatically when those conditions are met.

Alerts use a schedule to periodically evaluate a query result and take action if the condition evaluates to TRUE.

Example:

CREATE ALERT my_alert

IF (SELECT COUNT(*) FROM my_table WHERE status = 'ERROR') > 0

SCHEDULE = '5 MINUTE'

ACTION = CALL notify_error_procedure();

Why Other Options Are Incorrect:

B. External tables: Used to query external data but cannot trigger actions.

C. Secure views: Ensure data privacy but do not perform actions.

D. Materialized views: Improve performance by precomputing query results but do not perform periodic actions.

References:

Snowflake Alerts Documentation

In Snowflake, a Share is the object that contains all the information required to share a database with other Snowflake accounts. Shares are used to securely share data stored in Snowflake tables and views, enabling data providers to grant data consumers access to their datasets without duplicating data. When a database is shared, it can include one or more schemas, and each schema can contain tables, views, or both.

References:

Snowflake Documentation on Shares: Shares

In Auto-scale mode, a Snowflake multi-cluster virtual warehouse dynamically adds or removes clusters to process queued queries efficiently.

This ensures that workloads are handled quickly without manual intervention, especially during peak demand.

References:

Snowflake Documentation: Multi-Cluster Warehouses

Snowflake Scaling Policies

Network Policies in Snowflake define the IP address ranges allowed to connect to the Snowflake account.

Precedence of network policies:

Account-Level Policies (Highest Precedence): Apply to the entire Snowflake account and override lower-level policies.

User-Level Policies: Apply to individual users but are secondary to account-level policies.

Security Integrations: Used for external integrations and have lower precedence.

Why Other Options Are Incorrect:

C. Database / D. User: Database policies do not exist for network configurations, and user-level policies are secondary to account-level ones.

A. Security Integration: Lower precedence than account-level policies.

References:

Network Policy Documentation

To handle a large number of complex queries, configuring the warehouse in auto-scale mode by increasing the number of warehouse clusters is recommended. This setup allows Snowflake to dynamically add clusters as demand increases, ensuring better performance and concurrency. Increasing the number of clusters provides scalability for concurrent users and heavy workloads, improving response times without impacting individual query performance.

For users assigned the ACCOUNTADMIN role, Snowflake recommends enforcing Multi-Factor Authentication (MFA) to enhance security. The ACCOUNTADMIN role has extensive permissions, making it crucial to secure accounts held by such users against unauthorized access. MFA adds an additional layer of security by requiring a second form of verification beyond just the username and password, significantly reducing the risk of account compromise.References: Snowflake Security Best Practices

Snowflake's governance features vary across different editions, but the OBJECT_DEPENDENCIES view is supported by all Snowflake editions. This feature is part of Snowflake's Information Schema and is designed to help users understand the dependencies between various objects in their Snowflake environment.

The OBJECT_DEPENDENCIES view provides a way to query and analyze the relationships and dependencies among different database objects, such as tables, views, and stored procedures. This is crucial for governance, as it allows administrators and data engineers to assess the impact of changes, understand object relationships, and ensure proper management of data assets.

Object tags, masking policies, and row access policies are more advanced features that offer fine-grained data governance capabilities such as tagging objects for classification, dynamically masking sensitive data based on user roles, and controlling row-level access to data. These features may have varying levels of support across different Snowflake editions, with some features being exclusive to higher-tier editions.

Snowflake’s data architecture is based on a multi-cluster, shared data model.

It decouples compute and storage, enabling multiple virtual warehouses (clusters) to access the same shared data concurrently without impacting each other.

This ensures scalability, concurrency, and high performance.

References:

Snowflake Documentation: Architecture Overview

Using database roles provides more granular control over access to objects for different user groups, compared to granting privileges directly to a share.

Database roles allow administrators to group and manage privileges, making it easier to adjust access policies without directly modifying shares.

References:

Snowflake Documentation: Database Roles

Secure Data Sharing Best Practices

To prevent backlogs of queued SQL statements:

STATEMENT_QUEUED_TIMEOUT_IN_SECONDS (A): Sets a timeout for how long a query can wait in the queue. Queries that exceed this time are terminated, preventing long queues.

MAX_CONCURRENCY_LEVEL (D): Controls the maximum number of concurrent queries the virtual warehouse can execute. Increasing this value reduces queuing.

Why Other Options Are Incorrect:

B. STATEMENT_TIMEOUT_IN_SECONDS: Defines the total execution time for queries, not queuing behavior.

C. DATA_RETENTION_TIME_IN_DAYS: Related to table retention policies, not query concurrency.

E. MAX_DATA_EXTENSION_TIME_IN_DAYS: Related to time travel, not query queuing.

References:

Managing Query Concurrency

The Query Profile tool in Snowflake provides detailed execution statistics for queries, including execution time, micro-partition scans, and caching information.

It is available to users at no additional cost and is accessible via the Snowflake UI.

References:

Snowflake Documentation: Query Profile

Query Optimization in Snowflake

To restrict access to Snowsight from a specific location, a network policy must be configured.

The network policy allows only specific IP addresses (e.g., home or office networks) to access the Snowflake account.

Example:

CREATE NETWORK POLICY my_policy

ALLOWED_IP_LIST = ('192.168.1.1', '203.0.113.0/24');

ALTER ACCOUNT SET NETWORK_POLICY = my_policy;

References:

Snowflake Documentation: Network Policies

In the execution time summary of a Query Profile in Snowflake, the categories included provide insights into various aspects of query execution. "Pruning" refers to the process by which Snowflake reduces the amount of data scanned by eliminating partitions of data that are not relevant to the query, thus improving performance. "Initialization" represents the time taken for query planning and setup before actual execution begins. These metrics are crucial for understanding and optimizing query performance.

Snowflake supports a variety of subquery types, including both correlated and uncorrelated subqueries. The correct answers are B and E, which highlight Snowflake's flexibility in handling subqueries within SQL queries.

Uncorrelated Scalar Subqueries: These are subqueries that can execute independently of the outer query. They return a single value and can be used anywhere a value expression is allowed, offering great flexibility in SQL queries.

EXISTS, ANY/ALL, and IN Subqueries: These subqueries are used in WHERE clauses to filter the results of the main query based on the presence or absence of matching rows in a subquery. Snowflake supports both correlated and uncorrelated versions of these subqueries, providing powerful tools for complex data analysis scenarios.

Examples and Usage:

Uncorrelated Scalar Subquery:

SELECT * FROM employees WHERE salary > (SELECT AVG(salary) FROM employees);

Correlated EXISTS Subquery:

SELECT * FROM orders o WHERE EXISTS (SELECT 1 FROM customer c WHERE c.id = o.customer_id AND c.region = 'North America');

In Snowflake, the APPLY privilege is required to set a masking policy on a table or view column. This privilege allows a user to associate a masking policy with a specific column, thereby controlling how data in that column is masked or hidden.

Create a Masking Policy: Define a masking policy using the CREATE MASKING POLICY command.

Grant APPLY Privilege: Grant the APPLY privilege on the masking policy to the relevant roles or users.

Apply the Masking Policy: Use the ALTER TABLE or ALTER VIEW command to apply the masking policy to a column.

References:

Snowflake Documentation: Data Masking

Snowflake Documentation: CREATE MASKING POLICY

Snowflake Documentation: Privileges for Masking Policies

Snowpipe uses key-based authentication for its REST endpoints. This involves generating and using a key pair (public and private keys) to securely authenticate API requests.

Generate Key Pair: Generate a public and private key pair.

Register Public Key: Register the public key with the Snowflake user that will be making the API requests.

Authenticate Requests: Use the private key to sign API requests sent to Snowpipe REST endpoints.

References:

Snowflake Documentation: Key Pair Authentication & Key Rotation

Snowflake Documentation: Using Snowpipe REST API

The ACCESS_HISTORY view in the ACCOUNT_USAGE schema provides details about data and user activity within Snowflake.

Key uses for reviewing governance settings:

A. Identify queries run by a particular user: Tracks the SQL statements executed by a user.

D. Identify objects that were modified by a query: Displays the objects affected (e.g., tables or views) by each query.

References:

Snowflake Documentation: ACCESS_HISTORY View

Governance with Account Usage Views

https://docs.snowflake.com/en/sql-reference/data-sharing-usage

The ACCESS_HISTORY view in Snowflake provides detailed information about queries executed in the account, including metadata such as the time of execution, the user, and the SQL text of the queries. This view is available in the Snowflake Enterprise edition and higher editions. The Standard edition does not include this feature.

References:

Snowflake Documentation: Access History

Snowflake Editions: Snowflake Pricing

When using the SAMPLE clause in a query, if the seed is not set, Snowflake will use a different random seed for each execution of the query. This results in different rows being sampled each time, leading to different results. Setting a seed ensures that the same rows are sampled each time the query is run.

References:

Snowflake Documentation: Sampling

When creating a virtual warehouse in Snowsight using the CREATE WAREHOUSE statement, the following properties are enabled by default:

AUTO_RESUME (D): Automatically resumes the warehouse when a query is issued.

AUTO_SUSPEND (E): Automatically suspends the warehouse after a period of inactivity.

References:

Snowflake Documentation: Virtual Warehouse Properties

The JAROWINKLER_SIMILARITY function in Snowflake returns an integer between 0 and 100, indicating the similarity of two strings based on the Jaro-Winkler similarity algorithm. This function is useful for comparing strings and determining how closely they match each other.

Understanding JAROWINKLER_SIMILARITY: The Jaro-Winkler similarity metric is a measure of similarity between two strings. The score is a number between 0 and 100, where 100 indicates an exact match and lower scores indicate less similarity.

Usage Example: To compare two strings and get their similarity score, you can use:

SELECT JAROWINKLER_SIMILARITY('string1', 'string2') AS similarity_score;

Application Scenarios: This function is particularly useful in data cleaning, matching, and deduplication tasks where you need to identify similar but not identical strings, such as names, addresses, or product titles.

 In Snowflake’s architecture, the Cloud Services layer is responsible for generating the query execution plan. This layer handles all the coordination, optimization, and management tasks, including query parsing, optimization, and compilation into an execution plan that can be processed by the Compute layer.

The FLATTEN function converts semi-structured data (e.g., JSON or XML) into a relational representation by expanding nested structures into rows.

Example:

SELECT FLATTEN(INPUT => PARSE_JSON('[{"key": "value1"}, {"key": "value2"}]'));

References:

Snowflake Documentation: FLATTEN Function

Snowflake Semi-Structured Data Handling

A stream in Snowflake tracks changes (e.g., inserts, updates, and deletes) to a table. Its offset advances only when the stream is consumed or re-created.

CREATE OR REPLACE STREAM triggers the stream to reset its offset, effectively advancing it by overwriting the existing stream definition.

Other operations like querying the stream (SELECT) or applying changes (INSERT) would also advance offsets, but only CREATE OR REPLACE affects the offset in this context.

Why Other Options Are Incorrect:

A. DESCRIBE STREAM: Does not affect the stream offset; it only retrieves metadata.

B. ALTER STREAM: Modifies the stream properties but does not advance the offset.

C. DROP STREAM: Deletes the stream but does not advance its offset.

References:

Snowflake Streams Documentation

 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.

The ResultSet cache is leveraged to quickly return results for repeated queries. Actions that prevent leveraging this cache include stopping the virtual warehouse that the query is running against (B) and executing the RESULTS_SCAN() table function (D). Stopping the warehouse clears the local disk cache, including the ResultSet cache1. The RESULTS_SCAN() function is used to retrieve the result of a previously executed query, which bypasses the need for the ResultSet cache.

 Snowflake’s architecture is described as a multi-cluster, shared data architecture. This design combines the simplicity of a shared-disk architecture with the performance and scale-out benefits of a shared-nothing architecture, using a central repository accessible from all compute nodes2.

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

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

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.

 In a Snowflake role hierarchy, the top-level role is ACCOUNTADMIN. This role has the highest level of privileges and is capable of performing all administrative functions within the Snowflake account

 In Snowflake, each size increase in virtual warehouses doubles the number of servers. Therefore, if a size Small virtual warehouse is made up of two servers, a Large warehouse, which is two sizes larger, would be made up of eight servers (2 servers for Small, 4 for Medium, and 8 for Large)2.

Size specifies the amount of compute resources available per cluster in a warehouse. Snowflake supports the following warehouse sizes:

https://docs.snowflake.com/en/user-guide/warehouses-overview.html

 When cloning a database in Snowflake, the clone includes all privileges on the database as well as existing child objects within the database, such as schemas, tables, views, etc. However, it does not include future child objects or privileges on schemas within the database2.

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

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

The Snowflake Search Optimization Service is designed to support improved performance for selective point lookup queries. These are queries that retrieve specific records from a database, often based on a unique identifier or a small set of criteria3.

 Row level security in Snowflake is available starting with the Enterprise edition. This feature allows for the creation of row access policies that can control access to data at the row level within tables and views

Snowflake supports the use of external stages with Amazon Web Services (AWS), Microsoft Azure Cloud, and Google Cloud Platform (GCP). These platforms allow users to stage data externally and integrate with Snowflake for data loading operations

 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.

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 SQL commands that consume a stream and advance the stream offset are those that result in changes to the data, such as UPDATE and INSERT operations. Specifically, ‘UPDATE TABLE FROM STREAM’ and ‘INSERT INTO TABLE SELECT FROM STREAM’ will consume the stream and move the offset forward, reflecting the changes made to the data.

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

Snowflake virtual warehouses support a configuration file and command line options in SnowSQL to specify a default warehouse, which is characteristic C. Additionally, the size of a virtual warehouse can be changed at any time, which is characteristic E. These features provide flexibility and ease of use in managing compute resources2.

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

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

 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

 For loading data into Snowflake via Snowpipe, the recommended compressed file size is between 100-250 MB. This size range is optimal for balancing the performance of parallel processing and minimizing the overhead associated with handling many small files2.

Snowflake’s architecture is designed to operate entirely on cloud infrastructure. It uses the core compute and storage services of each cloud provider, which allows it to leverage the scalability and reliability of cloud resources. Snowflake’s services are deployed across multiple availability zones within a cloud provider’s region to ensure high availability and fault tolerance. References: [COF-C02] SnowPro Core Certification Exam Study Guide

The Query Profile in Snowflake is used to identify performance issues with queries. Common issues that can be found using the Query Profile include identifying inefficient micro-partition pruning (D) and data spilling to a local or remote disk (E). Micro-partition pruning is related to the efficiency of query execution, and data spilling occurs when the memory is insufficient, causing the query to write data to disk, which can slow down the query performance1.

Operations that do not require compute resources are typically those that can leverage previously cached results. However, if no queries have been executed previously, all the given operations would require compute to execute. It’s important to note that certain operations like DDL statements and queries that hit the result cache do not consume compute credits2.

 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

Column-level security, which allows for the application of masking policies to columns in tables or views, is available starting from the Enterprise edition of Snowflake1.

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

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

 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.

 Snowflake’s Fail-safe provides a 7-day period during which data in a permanent table may be recoverable, but only by Snowflake Support, not by user operations3.

Worksheets in Snowsight can be shared directly with other Snowflake users within the same account. This feature allows for collaboration and sharing of SQL queries or Python code, as well as other data manipulation tasks1.

The features associated with Continuous Data Protection (CDP) that require additional Snowflake-provided data storage are Time Travel and Fail-safe. Time Travel allows users to access historical data within a defined period, while Fail-safe provides an additional layer of data protection beyond the Time Travel period. References: [COF-C02] SnowPro Core Certification Exam Study Guide

 Snowflake uses a Role-Based Access Control (RBAC) model to manage access to data and resources. Additionally, Snowflake ensures that all data is encrypted, both at rest and in transit, to provide a high level of security for data stored within the platform. References: [COF-C02] SnowPro Core Certification Exam Study Guide

To manage compliance with Personal Identifiable Information (PII) requirements, the Virtual Private Snowflake and Business Critical Editions of Snowflake should be used. These editions provide advanced security features necessary for handling sensitive data

When cloning a database containing stored procedures and regular views with fully qualified table references, the cloned views and stored procedures will reference the cloned tables in the cloned database (A). This ensures that the cloned database is a self-contained copy of the original, with all references pointing to objects within the same cloned database. References: SnowPro Core Certification cloning database stored procedures views

 Snowflake supports unloading data in JSON and delimited file formats such as CSV and TSV. These formats are commonly used for data interchange and are supported by Snowflake for unloading operations

Best practices for using the ACCOUNTADMIN role include ensuring that all users with this role use Multi-factor Authentication (MFA) for added security. Additionally, it is recommended to assign the ACCOUNTADMIN role to at least two users to avoid delays in case of password recovery issues, but to as few users as possible to maintain strict control over account-level operations4.

 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 credit consumption for maintaining a materialized view is impacted by how often the base table changes © and whether the materialized view has a cluster key defined (D). Changes to the base table can trigger a refresh of the materialized view, consuming credits. Additionally, having a cluster key defined can optimize the performance and credit usage during the materialized view’s maintenance. References: SnowPro Core Certification materialized view credit consumption

 Best practices for loading data into Snowflake include aiming for data file sizes between 100 MB and 250 MB when compressed, as this size is optimal for parallel processing and minimizes overhead. Enclosing fields with delimiter characters in quotes ensures proper field recognition during the load process. Splitting large files into smaller ones allows for better distribution of the load across compute resources, enhancing performance and efficiency.

The LOGIN_HISTORY view in the ACCOUNT_USAGE schema provides information about login attempts, including both successful and failed logins. This view can be used to review the failed login attempts of a specific user for the past 30 days. References: [COF-C02] SnowPro Core Certification Exam Study Guide

The maximum size limit for a record of a VARIANT data type in Snowflake is 16MB. This allows for storing semi-structured data types like JSON, Avro, ORC, Parquet, or XML within a single VARIANT column. References: Based on general database knowledge as of 2021.

 In Snowflake, a namespace is comprised of a database and a schema. The combination of a database and schema uniquely identifies database objects within an account

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 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.

 When unloading data, Snowflake assigns each file a unique name to ensure there is no overlap or confusion between files. This is part of the bulk unloading process where data is exported from Snowflake tables into flat files3.

 Snowflake reorganizes data into its internal optimized, compressed, columnar format in the Database Storage layer. This process is part of how Snowflake manages data storage, ensuring efficient data retrieval and query performance

 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 an additional 30 seconds, it is billed for another 60 seconds (the minimum charge for a restart), totaling 121 seconds2

 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 VARIANT data type in Snowflake can store multiple types of data structures, as it is designed to hold semi-structured data. It can contain any other data type, including OBJECT and ARRAY, which allows it to represent various data structures

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 be used for further processing within Snowflake3.

 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.

To optimize query performance in Snowflake, users can cluster a table, which organizes the data in a way that minimizes the amount of data scanned during queries. Additionally, enabling the search optimization service can improve the performance of selective point lookup queries on large tables34.

 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 Snowflake URL type used by directory tables is the scoped URL. This type of URL provides access to files in a stage with metadata, such as the Snowflake file URL, for each file

Snowflake recommends using columns with very high cardinality and those that are most actively used in selective filters as clustering keys. High cardinality columns have a wide range of unique values, which helps in evenly distributing the data across micro-partitions. Columns used in selective filters help in pruning the number of micro-partitions to scan, thus improving query performance. References: Based on general database optimization principles.

 Snowflake allows data providers to share data with consumers across different cloud platforms and regions through database replication. The data provider must replicate the database to a secondary account in the target region or cloud platform within the same organization, and then create a share to the data consumer’s account. This process ensures that the data is available in the consumer’s region and on their cloud platform, facilitating seamless data sharing. References: Sharing data securely across regions and cloud platforms | Snowflake Documentation

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

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 FLATTEN table function in Snowflake is used to convert semi-structured data, such as JSON or XML, into a relational format. It expands nested arrays or objects into multiple rows, making the data suitable for relational querying3.

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

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

 Snowflake maintains a result cache that stores the results of every query for 24 hours. If the same query is executed again within this time frame and the data has not changed, Snowflake will retrieve the data from the result cache instead of using a virtual warehouse to recompute the results2.

 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.

 Snowflake allows for only one resource monitor to be assigned at the account level. This monitor oversees the credit usage of all the warehouses in the account. References: Snowflake Documentation

Credit charges for Snowflake virtual warehouses are calculated based on the size of the virtual warehouse and the length of time the warehouse is running. The size determines the compute resources available, and charges are incurred for the time these resources are utilized

 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.

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.

Snowflake’s virtual warehouses are responsible for query execution. They are clusters of compute resources that execute SQL statements, perform DML operations, and load data into tables

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 secure view in Snowflake is exposed only to users with the OWNERSHIP privilege. This privilege ensures that only authorized users who own the view, or roles that include ownership, can access the secure view

To run a multi-cluster warehouse in maximized mode, a user should set the minimum and maximum number of clusters to the same value. This ensures that all clusters are available when the warehouse is started, providing maximum resources for query execution. References: Snowflake Documentation2.

 Periodic rekeying of micro-partitions is a feature that requires the Enterprise Edition of Snowflake or higher. This feature is part of Snowflake’s comprehensive approach to encryption key management, ensuring data security through regular rekeying1. References: [COF-C02] SnowPro Core Certification Exam Study Guide

 To monitor data storage for individual tables, the commands and objects that can be used are ‘SHOW STORAGE BY TABLE;’ and the Information Schema view ‘TABLE_STORAGE_METRICS’. These tools provide detailed information about the storage utilization for tables. References: Snowflake Documentation

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

 When a view is defined on a permanent table, and a temporary table with the same name is created in the same schema, the query from the view will return the data from the permanent table. Temporary tables are session-specific and do not affect the data returned by views defined on permanent tables2.

 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 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.

 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

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.

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

 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.

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

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

Secure sharing in Snowflake allows users to share specific objects with other Snowflake accounts without physically copying the data, thus not consuming additional storage. Tables and Secure User Defined Functions (UDFs) are among the objects that can be shared using this feature. Materialized views, sequences, and procedures are not shareable objects in Snowflake.

References:

[COF-C02] SnowPro Core Certification Exam Study Guide

Snowflake Documentation on Secure Data Sharing1

The PUT command is used to load data into an internal stage in Snowflake. This command uploads data files from a local file system to a named internal stage, making the data available for subsequent loading into a Snowflake table using the COPY INTO command.

References:

[COF-C02] SnowPro Core Certification Exam Study Guide

Snowflake Documentation on Data Loading

 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

Snowflake supports two geospatial data types: GEOGRAPHY and GEOMETRY. The GEOGRAPHY data type is used to store geospatial data that models the Earth as a perfect sphere, which is suitable for global geospatial data. This data type follows the WGS 84 standard and is used for storing points, lines, and polygons on the Earth’s surface. The GEOMETRY data type, on the other hand, represents features in a planar (Euclidean, Cartesian) coordinate system and is typically used for local spatial reference systems. Since the question specifically asks about geospatial data, which commonly refers to Earth-related spatial data, the correct answer is GEOGRAPHY3. References: [COF-C02] SnowPro Core Certification Exam Study Guide

 The COPY INTO command in Snowflake can be configured to output data into a single file by setting the MAX_FILE_NUMBER option to 1. This option limits the number of files generated by the command, ensuring that only one file is created regardless of the amount of data being exported.

References:

[COF-C02] SnowPro Core Certification Exam Study Guide

Snowflake Documentation on Data Unloading

 To view warehouse usage over time, the Query history view and the WAREHOUSE_METERING__HISTORY View can be utilized. The Query history view allows users to monitor the performance of their queries and the load on their warehouses over a specified period1. The WAREHOUSE_METERING__HISTORY View provides detailed information about the workload on a warehouse within a specified date range, including average running and queued loads2. References: [COF-C02] SnowPro Core Certification Exam Study Guide

 Query compilation in Snowflake occurs in the Cloud Services layer. This layer is responsible for coordinating and managing all aspects of the Snowflake service, including authentication, infrastructure management, metadata management, query parsing and optimization, and security. By handling these tasks, the Cloud Services layer enables the Compute layer to focus on executing queries, while the Storage layer is dedicated to persistently storing data.

References:

[COF-C02] SnowPro Core Certification Exam Study Guide

Snowflake Documentation on Snowflake Architecture1

Secure data sharing in Snowflake allows users to share various objects between Snowflake accounts without physically copying the data, thus not consuming additional storage. Among the options provided, external tables can be shared through secure data sharing. External tables are used to query data directly from files in a stage without loading the data into Snowflake tables, making them suitable for sharing across different Snowflake accounts.

References:

Snowflake Documentation on Secure Data Sharing

SnowPro™ Core Certification Companion: Hands-on Preparation and Practice

 To address a high volume of queries queuing in a warehouse, Snowflake recommends two best practices:

A. Use multi-clustered warehousing to scale out warehouse capacity: This approach allows for the distribution of queries across multiple clusters within a warehouse, effectively managing the load and reducing the queue volume.

B. Scale up the warehouse size to allow Queries to execute faster: Increasing the size of the warehouse provides more compute resources, which can reduce the time it takes for queries to execute and thus decrease the number of queries waiting in the queue.

These strategies help to optimize the performance of the warehouse by ensuring that resources are scaled appropriately to meet demand.

References:

Snowflake Documentation on Multi-Cluster Warehousing

SnowPro Core Certification best practices

 Virtual Warehouses in Snowflake can indeed be resized while they are suspended. Resizing a warehouse involves changing the number of compute resources (servers) allocated to it, which can be done to adjust performance and cost. When a warehouse is suspended, it is not currently running any queries, but its definition and metadata remain intact, allowing for modifications like resizing.

In Snowflake, Data Shares can be created and managed in two primary ways:

Via the Snowflake Web Interface (UI): Users can create and manage shares through the graphical interface provided by Snowflake, which allows for a user-friendly experience.

Via SQL commands: Snowflake also allows the creation and management of shares using SQL commands. This method is more suited for users who prefer scripting or need to automate the process.

 In a CREATE PIPE ... AS COPY ... FROM (....) statement, the supported transformations include filtering data using an optional WHERE clause and omitting columns. The WHERE clause allows for the specification of conditions to filter the data that is being loaded, ensuring only relevant data is inserted into the table. Omitting columns enables the exclusion of certain columns from the data load, which can be useful when the incoming data contains more columns than are needed for the target table.

References:

[COF-C02] SnowPro Core Certification Exam Study Guide

Simple Transformations During a Load1

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

 Materialized views in Snowflake are a feature that allows for the pre-computation and storage of query results for faster query performance. This feature is available starting from the Enterprise Edition of Snowflake. It is not available in the Standard Edition, and while it is also available in higher editions like Business Critical and Virtual Private Snowflake, the Enterprise Edition is the minimum requirement.

References:

Snowflake Documentation on CREATE MATERIALIZED VIEW1.

Snowflake Documentation on Working with Materialized Views

https://docs.snowflake.com/en/sql-reference/sql/create-materialized-view.html#:~:text=Materialized%20views%20require%20Enterprise%20Edition,upgrading%2C%20please%20contact%20Snowflake%20Support .

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 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

 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

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

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)

The correct command to view all roles granted to a specific user in Snowflake is SHOW GRANTS TO USER ;. This command lists all access control privileges that have been explicitly granted to the specified user. References: SHOW GRANTS | Snowflake Documentation

 In all Snowflake editions, two key capabilities are universally available:

B. Automatic encryption of all data: Snowflake automatically encrypts all data stored in its platform, ensuring security and compliance with various regulations. This encryption is transparent to users and does not require any configuration or management.

D. Object-level access control: Snowflake provides granular access control mechanisms that allow administrators to define permissions at the object level, including databases, schemas, tables, and views. This ensures that only authorized users can access specific data objects.

These features are part of Snowflake’s commitment to security and governance, and they are included in every edition of the Snowflake Data Cloud.

References:

Snowflake Documentation on Security Features

SnowPro® Core Certification Exam Study Guide

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 .

Alation is known for specializing in data catalog solutions and is a partner of Snowflake. Data catalog solutions are essential for organizations to effectively manage their metadata and make it easily accessible and understandable for users, which aligns with the capabilities provided by Alation.

References:

[COF-C02] SnowPro Core Certification Exam Study Guide

Snowflake’s official documentation and partner listings

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.

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.

References:

[COF-C02] SnowPro Core Certification Exam Study Guide

Snowflake Documentation on Snowpipe1

The primary responsibility of Snowflake’s virtual warehouses is to execute queries. Virtual warehouses are one of the key components of Snowflake’s architecture, providing the compute power required to perform data processing tasks such as running SQL queries, performing joins, aggregations, and other data manipulations.

References:

[COF-C02] SnowPro Core Certification Exam Study Guide

Snowflake Documentation on Virtual Warehouses1

When a CLUSTER BY clause is added to a Snowflake table, it specifies one or more columns to organize the data within the table’s micro-partitions. This clustering aims to colocate data with similar values in the same or adjacent micro-partitions. By doing so, it enhances the efficiency of query pruning, where the Snowflake query optimizer can skip over irrelevant micro-partitions that do not contain the data relevant to the query, thereby improving performance.

References:

Snowflake Documentation on Clustering Keys & Clustered Tables1.

Community discussions on how source data’s ordering affects a table with a cluster key

 External stages can be altered and dropped in Snowflake. An external stage points to an external location, such as an S3 bucket, where data files are stored. Users can modify the stage’s definition or drop it entirely if it’s no longer needed. This is in contrast to table stages, which are tied to specific tables and cannot be altered or dropped independently.

References:

[COF-C02] SnowPro Core Certification Exam Study Guide

Snowflake Documentation on Stages1

 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

 The COPY INTO command is used in Snowflake to unload data from a table into a file in a stage. This command allows for the export of data from Snowflake tables into flat files, which can then be used for further analysis, processing, or storage in external systems.

References:

Snowflake Documentation on Unloading Data

Snowflake SnowPro Core: Copy Into Command to Unload Rows to Files in Named Stage

 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

 Snowflake’s default Multi-Factor Authentication (MFA) service is powered by Duo Security. Users are required to install the Duo Mobile application on their devices to use MFA for increased login security when connecting to Snowflake. This service is managed entirely by Snowflake, and users do not need to sign up separately with Duo1.

 Snowflake supports several methods for authenticating users, including federated authentication, key-pair authentication, and OAuth. Federated authentication allows users to authenticate using their organization’s identity provider. Key-pair authentication uses a public-private key pair for secure login, and OAuth is an open standard for access delegation commonly used for token-based authentication. References: Authentication policies | Snowflake Documentation, Authenticating to the server | Snowflake Documentation, External API authentication and secrets | Snowflake Documentation.

Parquet is a columnar storage file format that is optimized for performance in Snowflake. It is designed to be efficient for both storage and query performance, particularly for complex queries on large datasets. Parquet files support efficient compression and encoding schemes, which can lead to significant savings in storage and speed in query processing, making it the most performant file format for loading data into Snowflake.

References:

[COF-C02] SnowPro Core Certification Exam Study Guide

Snowflake Documentation on Data Loading1

 One of the key features of Snowflake’s architecture is its unique approach to eliminating resource contention through the use of virtual warehouses. This is achieved by separating storage and compute resources, allowing multiple virtual warehouses to operate independently on the same data without affecting each other. This means that different workloads, such as loading data, running queries, or performing complex analytics, can be processed simultaneously without any performance degradation due to resource contention.

References:

Snowflake Documentation on Virtual Warehouses

SnowPro® Core Certification Study Guide

 Clustering keys in Snowflake work by sorting the designated columns over time. This process is done in the background and does not block data manipulation language (DML) operations, allowing for normal database operations to continue without interruption. The purpose of clustering keys is to organize the data within micro-partitions to optimize query performance1.

References:

[COF-C02] SnowPro Core Certification Exam Study Guide

Snowflake Documentation on Clustering1

 Clustering keys in Snowflake are used to reorganize large tables based on one or more columns. This feature optimizes the arrangement of data within micro-partitions to improve query performance, especially for large tables where efficient data retrieval is crucial. References: [COF-C02] SnowPro Core Certification Exam Study Guide

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

 Snowflake Time Travel is a powerful feature that allows users to access historical data within a defined period. It enables two key capabilities:

B. Restoring data-related objects that have been deleted within the past 90 days: Time Travel can be used to restore tables, schemas, and databases that have been accidentally or intentionally deleted within the Time Travel retention period.

C. Conducting point-in-time analysis for BI reporting: It allows users to query historical data as it appeared at a specific point in time within the Time Travel retention period, which is crucial for business intelligence and reporting purposes.

While Time Travel does allow querying of past data, it is limited to the retention period set for the Snowflake account, which is typically 1 day for standard accounts and can be extended up to 90 days for enterprise accounts. It does not enable querying or restoring objects created or deleted beyond the retention period, nor does it provide analysis over all periods of time.

References:

Snowflake Documentation on Time Travel

SnowPro® Core Certification Study Guide