Practice Questions For Azure Data DP-900 Fundamentals Exam Pt.3
157. What is a security principal?
An object that represents a user, group, service, or managed identity that is requesting access to Azure resources.
148. When you configure CosmosDB for replication what is the default behavior?
By default, only the region in which you created the account supports write operations; the replicas are all read-only.
115. What are the disadvantages of using Azure Table Storage?
Consistency needs to be given consideration as transactional updates across multiple entities aren't guaranteed There's no referential integrity; any relationships between rows need to be maintained externally to the table It's difficult to filter and sort on non-key data. Queries that search based on non-key fields could result in full table scans
155. Which consistency option of CosmosDB provides the lowest latency and least consistency?
Eventual Consistency
112. What are point queries and range queries in Azure Table Storage?
In a point query, when an application retrieves a single row, the partition key enables Azure to quickly hone in on the correct partition, and the row key lets Azure identify the row in that partition. In a range query, the application searches for a set of rows in a partition, specifying the start and end point of the set as row keys. This type of query is also very quick, as long as you have designed your row keys according to the requirements of the queries performed by your application.
127. Which feature should you enable if you want to recover a blob that has been removed or overwritten by accident?
Soft Delete
123. How many access tiers that Blob Storage provides?
The Hot tier is the default. You use this tier for blobs that are accessed frequently. The blob data is stored on high-performance media. The Cool tier. This tier has lower performance and incurs reduced storage charges compared to the Hot tier. Use the Cool tier for data that is accessed infrequently. It's common for newly created blobs to be accessed frequently initially, but less so as time passes. In these situations, you can create the blob in the Hot tier, but migrate it to the Cool tier later. You can migrate a blob form the Cool tier back to the Hot tier. The Archive tier. This tier provides the lowest storage cost, but with increased latency. The Archive tier is intended for historical data that mustn't be lost, but is required only rarely. Blobs in the Archive tier are effectively stored in an offline state. Typical reading latency for the Hot and Cool tiers is a few milliseconds, but for the Archive tier, it can take hours for the data to become available. To retrieve a blob from the Archive tier, you must change the access tier to Hot or Cool. The blob will then be rehydrated. You can read the blob only when the rehydration process is complete.
129. What is the Change Feed option in Blob Storage Service?
The change feed for a blob provides an ordered, read-only, record of the updates made to a blob.
111. What is Azure table storage key comprises of?
The key in an Azure Table Storage table comprises two elements: * The partition key that identifies the partition containing the row * The row key that is unique to each row in the same partition. Items in the same partition are stored in row key order. If an application adds a new row to a table, Azure ensures that the row is placed in the correct position in the table.
160. Name some of the aggregate functions?
COUNT(p). This function returns a count of the number of instances of field p in the result set. To count all the items in the result set, set p to a scalar value, such as 1. SUM(p). This function returns the sum of all the instances of field p in the result set. The values of p must be numeric. AVG(p). This function returns the mathematical mean of all the instances of field p in the result set. The values of p must be numeric. MAX(p). This function returns the maximum value of field p in the result set. MIN(p). This function returns the minimum value of field p in the result set.
140. What are the elements of an Azure Table storage key?
Partition key and row key
138. Cosmos DB guarantees less than 10-ms latencies for both reads (indexed) and writes at the 99th percentile all around the world. Is this true?,
True
104. What is Azure Table Storage?
Azure Table Storage is a scalable key-value store held in the cloud. You create a table using an Azure storage account. In an Azure Table Storage table, items are referred to as rows, and fields are known as columns.
159. What is the operator that you use as part of the SELECT clause to eliminate duplicates in the result data?
DISTINCT
113. You need to define a schema for Azure Table Storage. Is this correct?
False Azure Table Storage tables are schemaless. It's easy to adapt your data as the needs of your application evolve.
128. What are snapshots?
A snapshot is a read-only version of a blob at a particular point in time.
158. What is the advantage of using multi-region replication with Cosmos DB?
Availability is increased.
108. What is a partition in Azure Table Storage?
Partitioning is a mechanism for grouping related rows, based on common property or partition key. Rows that share the same partition key will be stored together. Partitioning not only helps to organize data, it can also improve scalability and performance
144. What are the several tools that you can use to provision services?
The Azure portal. The Azure command-line interface (CLI) Azure PowerShell Azure Resource Manager templates
153. What is the bounded Staleness option?
There's a lag between writing and then reading the updated data. You specify this staleness either as a period of time, or number of previous versions the data will be inconsistent for.
151. What is Consistent Prefix Option?
This option ensures that changes will appear in order, although there may be a delay before they become visible. In this period, applications may see old data.
142. Why might you use Azure File storage?
To enable users at different sites to share files.
117. Azure Table Storage is intended to support very large volumes of data up to several hundred TBs in size. Is this correct?
True
141. When should you use a block blob and when should you use a page blob?
Use a page block for blobs that require random read and write access. Use a block blob for discrete objects that change infrequently.
126. What should you do if you want to maintain and restore earlier versions of a blob?
Versioning
106. Azure Table Storage tables have no concept of relationships
stored procedures, secondary indexes, or foreign keys. Is this true?,True
152. What is the Session option?
If an application makes a number of changes, they'll all be visible to that application, and in order. Other applications may see old data, although any changes will appear in order, as they did for the Consistent Prefix option. This form of consistency is sometimes known as read your own writes.
139. What are some of the scenarios where CosmosDB is suitable?
IoT and telematics. These systems typically ingest large amounts of data in frequent bursts of activity. Cosmos DB can accept and store this information very quickly. The data can then be used by analytics services, such as Azure Machine Learning, Azure HDInsight, and Power BI. Additionally, you can process the data in real-time using Azure Functions that are triggered as data arrives in the database. Retail and marketing. Microsoft uses CosmosDB for its own e-commerce platforms that run as part of Windows Store and Xbox Live. It's also used in the retail industry for storing catalog data and for event sourcing in order processing pipelines. Gaming. The database tier is a crucial component of gaming applications. Modern games perform graphical processing on mobile/console clients, but rely on the cloud to deliver customized and personalized content like in-game stats, social media integration, and high-score leaderboards. Games often require single-millisecond latencies for reads and write to provide an engaging in-game experience. A game database needs to be fast and be able to handle massive spikes in request rates during new game launches and feature updates. Web and mobile applications. Azure Cosmos DB is commonly used within web and mobile applications, and is well suited for modeling social interactions, integrating with third-party services, and for building rich personalized experiences. The Cosmos DB SDKs can be used to build rich iOS and Android applications using the popular Xamarin framework.
114. What are the advantages of using Azure Table Storage?
It's simpler to scale. It takes the same time to insert data in an empty table, or a table with billions of entries. An Azure storage account can hold up to 500 TB of data. A table can hold semi-structured data There's no need to map and maintain the complex relationships typically required by a normalized relational database. Row insertion is fast Data retrieval is fast, if you specify the partition and row keys as query criteria
118. You need to create a storage account before creating an Azure Table Storage. Is this correct?
True
109. Can these partitions grow or shrink as required?
Yes Partitions are independent from each other, and can grow or shrink as rows are added to, or removed from, a partition. A table can contain any number of partitions.
124. You are saving objects into Blob Storage with Hot tier and you want to move these files after 6 months to the Archive tier as we no longer need to access the files. How do you handle this scenario?
You can create lifecycle management policies for blobs in a storage account. A lifecycle management policy can automatically move a blob from Hot to Cool, and then to the Archive tier, as it ages and is used less frequently (policy is based on the number of days since modification).
154. What is a strong consistency option?
all writes are only visible to clients after the changes are confirmed as written successfully to all replicas. This option is unavailable if you need to distribute your data across multiple global regions.
143. You are building a system that monitors the temperature throughout a set of office blocks and sets the air conditioning in each room in each block to maintain a pleasant ambient temperature. Your system has to manage the air conditioning in several thousand buildings spread across the country/region and each building typically contains at least 100 air-conditioned rooms. What type of NoSQL datastore is most appropriate for capturing the temperature data to enable it to be processed quickly?
Send the data to an Azure Cosmos DB database and use Azure Functions to process the data.
125. What are the use cases of Azure Blob Storage?
Serving images or documents directly to a browser, in the form of a static website. Storing files for distributed access Streaming video and audio Storing data for backup and restore, disaster recovery, and archiving Storing data for analysis by an on-premises or Azure-hosted service
132. How do you upload files into Azure File Storage?
You can upload files to Azure File Storage using the Azure portal, or tools such as the AzCopy utility. You can also use the Azure File Sync service to synchronize locally cached copies of shared files with the data in Azure File Storage.
156. What is the shared access signature?
You can use shared access signatures (SAS) to grant limited rights to resources in an Azure storage account for a specified time period. This feature enables applications to access resources such as blobs and files, without requiring that they're authenticated first.
103. What is the Azure service that implements the NoSQL key-value model?
Azure Table Storage
134. What are some of the use cases of Azure File Storage?
Migrate existing applications to the cloud. Share server data across on-premises and cloud. Integrate modern applications with Azure File Storage. Simplify hosting High Availability (HA) workload data.
120. You need to create a storage account before creating an Azure Blob Storage. Is this correct?
True
122. You control who can read and write blobs inside a container at the container level. Is this true?
True
136. What is Azure Cosmos DB?
Azure Cosmos DB is a multi-model NoSQL database management system. Cosmos DB manages data as a partitioned set of documents. A document is a collection of fields, identified by a key. The fields in each document can vary, and a field can contain child documents. Many document databases use JSON (JavaScript Object Notation) to represent the document structure. In this format, the fields in a document are enclosed between braces, { and }, and each field is prefixed with its name. Cosmos DB is a highly scalable database management system. Cosmos DB automatically allocates space in a container for your partitions, and each partition can grow up to 10 GB in size. Indexes are created and maintained automatically.
130. What is Azure File Storage?
Azure File Storage enables you to create files shares in the cloud, and access these file shares from anywhere with an internet connection.
131. What are the features of Azure File Storage?
Azure File Storage enables you to share up to 100 TB of data in a single storage account. The maximum size of a single file is 1 TiB Azure File Storage supports up to 2000 concurrent connections per shared file.
133. How many tiers that Azure File Storage Offers?
Azure File Storage offers two performance tiers. The Standard tier uses hard disk-based hardware in a datacenter, and the Premium tier uses solid-state disks. The Premium tier offers greater throughput, but is charged at a higher rate.
147. What are the options for protecting Azure resources such as storage account Azure cosmos DB, etc?
Azure Private Endpoint Firewalls and virtual networks Configure authentication Configure access control Configure advanced security
105. You have semi-structured data and you want to store that data in the database as key-value pairs where the key is unique and columns can vary and each row holding the entire data for a logical entity. Which storage option should you select?
Azure Table Storage
107. Why Azure Table Storage provides much faster access to the data you need?
Azure Table Storage provides much faster access to the data because the data is available in a single row, without requiring that you perform joins across relationships. To help ensure fast access, Azure Table Storage splits a table into partitions.
121. What are the different types of the blob that Azure Blob Service Supports?
Block blobs: A block blob is handled as a set of blocks. Each block can vary in size, up to 100 MB. A block blob can contain up to 50,000 blocks, giving a maximum size of over 4.7 TB. The block is the smallest amount of data that can be read or written as an individual unit. Block blobs are best used to store discrete, large, binary objects that change infrequently. Page blobs: A page blob is organized as a collection of fixed size 512-byte pages. A page blob is optimized to support random read and write operations; you can fetch and store data for a single page if necessary. A page blob can hold up to 8 TB of data. Azure uses page blobs to implement virtual disk storage for virtual machines. Append blobs: An append blob is a block blob optimized to support append operations. You can only add blocks to the end of an append blob; updating or deleting existing blocks isn't supported. Each block can vary in size, up to 4 MB. The maximum size of an append blob is just over 195 GB.
135. You shouldn't use Azure File Storage for files that can be written by multiple concurrent processes simultaneously. Why?
Don't use Azure File Storage for files that can be written by multiple concurrent processes simultaneously. Multiple writers require careful synchronization, otherwise the changes made by one process can be overwritten by another. The alternative solution is to lock the file as it is written, and then release the lock when the write operation is complete. However, this approach can severaly impact concurrency and limit performance.
145. What is replication and how many options we have when provisioning a Storage account?
Replication. Data in an Azure Storage account is always replicated three times in the region you specify as the primary location for the account. Azure Storage offers two options for how your data is replicated in the primary region: Locally redundant storage (LRS) copies your data synchronously three times within a single physical location in the region. LRS is the least expensive replication option, but isn't recommended for applications requiring high availability. Geo-redundant storage (GRS) copies your data synchronously three times within a single physical location in the primary region using LRS. It then copies your data asynchronously to a single physical location in the secondary region. This form of replication protects you against regional outages. Read-access geo-redundant storage (RA-GRS) replication is an extension of GRS that provides direct read-only access to the data in the secondary location. In contrast, the GRS option doesn't expose the data in the secondary location, and it's only used to recover from a failure in the primary location. RA-GRS replication enables you to store a read-only copy of the data close to users that are located in a geographically distant location, helping to reduce read latency times.
137. What are the different APIs that Cosmos DB supports?
SQL API. This interface provides a SQL-like query language over documents, enable to identify and retrieve documents using SELECT statements. Table API. This interface enables you to use the Azure Table Storage API to store and retrieve documents. The purpose of this interface is to enable you to switch from Table Storage to Cosmos DB without requiring that you modify your existing applications. MongoDB API. MongoDB is another well-known document database, with its own programmatic interface. Many organizations run MongoDB on-premises. You can use the MongoDB API for Cosmos DB to enable a MongoDB application to run unchanged against a Cosmos DB database. Cassandra API. Cassandra is a column family database management system. This is another database management system that many organizations run on-premises. The Cassandra API for Cosmos DB provides a Cassandra-like programmatic interface for Cosmos DB. Cassandra API requests are mapped to Cosmos DB document requests. Gremlin API. The Gremlin API implements a graph database interface to Cosmos DB. A graph is a collection of data objects and directed relationships. Data is still held as a set of documents in Cosmos DB, but the Gremlin API enables you to perform graph queries over data. Using the Gremlin API you can walk through the objects and relationships in the graph to discover all manner of complex relationships The primary purpose of the Table, MongoDB, Cassandra, and Gremlin APIs is to support existing applications. If you are building a new application and database, you should use the SQL API.
116. What are the use cases of Azure Table Storage?
Storing TBs of structured data capable of serving web scale applications. Examples include product catalogs for eCommerce applications, and customer information, where the data can be quickly identified and ordered by a composite key. In the case of a product catalog, the partition key could be the product category (such as footwear), and the row key identifies the specific product in that category (such as climbing boots). Storing datasets that don't require complex joins, foreign keys, or stored procedures, and that can be denormalized for fast access. In an IoT system, you might use Azure Table Storage to capture device sensor data. Each device could have its own partition, and the data could be ordered by the date and time each measurement was captured. Capturing event logging and performance monitoring data. Event log and performance information typically contain data that is structured according to the type of event or performance measure being recorded. The data could be partitioned by event or performance measurement type, and ordered by the date and time it was recorded. Alternatively, you could partition data by date, if you need to analyze an ordered series of events and performance measures chronologically. If you want to analyze data by type and date/time, then consider storing the data twice, partitioned by type, and again by date. Writing data is fast, and the data is static once it has been recorded.
150. What is eventual consistency?
This option is the least consistent. It's based on the situation just described. Changes won't be lost, they'll appear eventually, but they might not appear immediately. Additionally, if an application makes several changes, some of those changes might be immediately visible, but others might be delayed; changes could appear out of order.
146. The default connectivity for Azure Cosmos DB and Azure Storage is to enable access to the world at large. You can connect to these services from an on-premises network the internet, or from within an Azure virtual network. Is this correct?
True
161. A container provides a convenient way of grouping related blobs together and you can organize blobs in a hierarchy of folders inside a container, similar to files in a file system on the disk. Is this true?
True
149. Replication is asynchronous for Cosmos DB. Is this true?
True Replication is asynchronous, so there's likely to be a lag between a change made in one region, and that change becoming visible in other regions.
110. How does partitioning help improving performance?
When you search for data, you can include the partition key in the search criteria. This helps to narrow down the volume of data to be examined, and improves performance by reducing the amount of I/O (reads and writes) needed to locate the data.
162. What is a command-line utility optimized for transferring large files (and blobs) between your local computer and Azure File storage?
AzCopy
119. What is Azure Blob Storage?
Azure Blob storage is a service that enables you to store massive amounts of unstructured data, or blobs, in the cloud.