# Which types of indexes are available in CosmosDB? - [x] range and spatial - [ ] secondary and primary key - [ ] secondary and spatial - [ ] range and primary key # You want to connect a DynamoDB stream to AWS Lambda function. Which one of these object do you create? - [ ] DynamoDB table - [x] DynamoDB trigger - [ ] DynamoDB item - [ ] DynamoDB index # To index a field that holds an array value in MongoDB, which index type do you create? - [ ] partial - [ ] sparse - [ ] compound - [x] multikey # You want to test HBASE on your laptop using the fewest number of steps. What do you do? - [ ] Set up Hadoop in pseudo-distributed mode. - [x] Set up HBASE in local mode. - [ ] Set up HBASE in pseudo-distributed mode. - [ ] Set up Hadoop in local mode. # You need to create a document database that supports database triggers. Which NoSQL database should you use? - [x] DynamoDB - [ ] BigTable - [ ] Redis - [ ] MongoDB # What is recommended size for Redis keys? - [ ] medium - [x] short - [ ] single bit - [ ] long # What does redis use to sort the elements of a sorted set? - [x] Scores. - [ ] Ids. - [ ] Values. - [ ] Keys. # You need to change the shard key of an existing MongoDB collection. What do you do? - [ ] Dump the collection data, drop the collection, create a new collection and shard key, import the data. - [ ] Add second shard key and drop the first shard key. - [x] Dump the collection data, drop the collection, presplit the data, create a new collection and shard key, import the data. - [ ] Drop and recreate the shard key. # Polyglot storage means using multiple types of what in the same application? - [ ] Security systems. - [ ] Database systems. - [x] Storage systems. - [ ] Query systems. # You need to implement the simplest possible scalable, in-memory cache for your AWS application. Which service do you select? - [ ] Elasticache using Memcached. - [ ] DynamoDB. - [ ] DynamoDB Accelerator (DAX). - [x] Elasticache using Redis. # You are doing data modelling for Google BigTable. Which statement expresses if and when you should split entities across multiple rows? - [ ] Keep all information for an entity in a single row. Store related entities in adjacent rows. - [ ] Keep all information for an entity in a single row. - [ ] Split entities across multiple rows if the entity data is over thousands of MBs, or if it does not need atomic updates and reads. - [x] Split entities across multiple rows if the entity data is over hundreds of MBs, or if it does not need atomic updates and reads. # Which two characteristics define Amazon Quantum Ledger Database? - [ ] Key-value data model; transactionally consistent with ACID semantics. - [x] Document data model; transactionally consistent with ACID semantics. - [ ] Key-value data model; transactions with tunable consistency. - [ ] Document data model; transactions with tunable consistency. # You need to design the primary key for DynamoDB based on three attributes. What do you do? - [ ] Designate all three fields as the primary key. - [x] Concatenate all three fields into one new field, then designate that new field as the primary key. - [ ] Designate two fields of the three fields as the primary key. - [ ] Concatenate two fields into one new field, then designate that new field and the remaining field as the primary key. # Which of these data types should you avoid in designing a Google Bigtable row key? - [ ] multi-valued identifiers - [ ] string identifiers - [ ] timestamps - [x] frequently updated identifiers # Your startup is building a prototype that has an evolving schema. Your data will be eventually consistent. Your application is hosted in AWS. Which database do you choose? - [ ] Neptune - [ ] DocumentDB - [x] DynamoDB - [ ] Amazon Aurora # You need to create a scalable database that allows you to share documents across authorized mobile clients in real time. What Google NoSQL database should you use? - [ ] Memorystore - [ ] Datastore - [x] Firebase - [ ] Bigtable # You need to design security for DynamoDB to allow users read-only access to certain items and attributes in a table. What do you do? - [ ] Use IAM roles. - [x] Use IAM policy conditions. - [ ] Use a VPC endpoint. - [ ] Use IAM policies. # Which statement is preferred Cypher code for Neo4j? - [ ] MATCH (:Person)-->(:Card)-->(:Company) RETURN count(vehicle) - [ ] Match (:Person)-->(:Car):(vehicle:Car)-->(:Company) RETURN count(vehicle) - [x] MATCH (:Person)-->(vehicle:Car)-->(:Company) RETURN count(vehicle) - [ ] MATCH (:Person)-->(:Card), (vehicle:Car)-->(:Company) RETURN count(vehicle) # You need multi-item ACID transactions with snapshot isolation within a partition for your cloud-based application. Which NoSQL databse do you choose? - [ ] Bigtable - [ ] GraphDB - [ ] DynamoDB - [x] Cosmos DB # You need to control your application's batch updates destination for your Bigtable multinode cluster. Which action do you take? - [ ] Create a custom app profile to route batch updates. - [ ] Create a custom app profile to route the batch update from that client. - [x] Update the default app profile to route the natch update from that client. - [ ] Use the default app profile to route batch updates. # Your query to verify that your Redis key is configured to support expiring user information on a defined interval returns -2, What does this value indicate? - [ ] The queried key value expired in the last two seconds. - [ ] The queried key value exists, but has no associated expire value. - [x] The queried key value does not exist. - [ ] There are two expired keys with this value. # You are designing a MongoDB schema to support queries that will include lookups. What should you do? - [ ] Create an index on the key value used as the primary key. - [ ] Create an index on the key value used as the foreign key. - [x] Create a multicolumn index on the key value used as the foreign key and the most unique column in the document. - [ ] Create a multicolumn index on the key value used as the primary and also the foreign key. # What is the aggregation operator for a join concept in MongoDB? - [ ] \$group - [ ] \$match - [x] \$lookup - [ ] \$project # For your mobile application, you need to select a Google cloud databse that can support compound, filtered document queries. Which do you choose? - [ ] Cloud SQL - [ ] Cloud Spanner - [x] Cloud Firestore - [ ] Cloud Firebase # To bulk load data into Amazon Neptune, what do you do? - [x] Upload data to S3 VPC endpoint, Use the Neptune loader to load from s3 into your Neptune instance - [ ] Ad data to a Kinesis stream, and use the Neptune loader to load from S# into your Neptune instance. - [ ] Add data to a Kinesis stream, and create a Kinesis stream VPC endpoint. Use the Neptune loader to load from S3 into your Neptune instance. - [ ] Upload data to S Use the Neptune loader to load from S3 into your Neptune instance. # You need to create a pub/sub server. Which database do you use? - [ ] Neo4j - [ ] Cassandra - [x] Redis - [ ] MyS## # SQL databases and NoSQL are which types of scalable? - [ ] horizontally, infinitely - [x] vertically, horizontally - [ ] vertically, infinitely - [ ] horizontally, vertically # You need to create a scalable database that allows you to query data nodes and edges efficiently. What do you use? - [ ] a relational database - [ ] a columnstore database - [ ] a document database - [x] a graph database # You are developing a model for a graph database. Your data will be moved from a relational database into Neo4j. Which of these transformations apply? - [ ] Rows become labels: bales become nodes. - [x] Tables become labels: rows become nodes. - [ ] Tables become collections: rows become items. - [ ] Rows become collections: tables become items. # You need to execute a command for MongoDB that does NOT load values from the `.mongorc.js` file. What do you do ? - [ ] Delete the .monorc.js file and restart mongo shell. - [ ] Use the mongo shell to create a command with --norc option - [ ] Rem all lines in the .mongorc.js file ad restart mongo shell. - [x] Use the mongo shell to create a command with --nodedefault option. # You need to store an unordered collection of name-value pairs with differing data types in DynamoDB. Which data type should you choose? - [x] map - [ ] set - [ ] list - [ ] stack # Which statement retrieves an item from the MusicCollection table in DynamoDB? - [ ] aws dynamodb query --table-name MusicCollection --key file://key.json - [x] aws dynamodb get-item --table-name MusicCollection --key file://key.json - [ ] aws dynamodb select --table-name MusicCollection --key file://key.json - [ ] aws dynamodb put-item --table-name MusicCollection --key file://key.json # Database availability is measured by which metric? - [ ] the amount of service calls - [ ] the number of minutes - [ ] the amount of service costs - [x] the number of nines # You need to encrypt data at rest in DynamoDB. Which action do you take? - [ ] You assign a default AWS encryption key to your table to encrypt data. - [ ] You create an AWS encryption key and assign it to your table to encrypt data. - [x] None. Data is encrypted by default. - [ ] You create an AWS encryption key and assign it to your database to encrypt data. # You need to generate a unique, sequential identifier for each value stored in a Redis cluster. What do you do? - [ ] Implement a SortedSet object to generate a value. - [ ] Use the GUID keyword to generate a value. - [ ] Implement a List object to generate a value. - [x] Use the INCR keyword to generate a value # You want to return a list of all elements in two Redis sets. Which keyword do you use? - [x] smembers - [ ] returnall - [ ] sunion - [ ] sismember # Which method shows you whether MongoDB uses any indexes when running a query, and how the indexes are used? - [ ] detailQueryExecution() - [ ] showPlan() - [x] explain() - [ ] describe() # Which statement accurately describes global secondary indexes in DynamoDB? - [ ] The global secondary indexes in DynamoDB are consistent, and are not guaranteed to return correct results. - [ ] The global secondary indexes in DynamoDB are transactionally consistent, and are guaranteed to return correct results. - [ ] The global secondary indexes in DynamoDB are partially consistent, and are not guaranteed to return correct results. - [x] The global secondary indexes in DynamoDB are eventually consistent, and are not guaranteed to return correct results. [reference link:](https://stackoverflow.com/questions/35414372/dynamodb-consistent-reads-for-global-secondary-index) # Which command do you use to add a value to a Redis stream named mystream? - [ ] ADD mystream \* sensor-id 1234 temperature 19.8 1518951480106-1 - [ ] UPDATE mystream \* sensor-id 1234 temperature 19.8 1518951480106-3 - [x] XADD mystream \* sensor-id 1234 temperature 9.8 1518951480106-0 - [ ] INSERT mystream \* sensor-d 1234 temperature 19.8 15181480106-2 # Which code example completes this statement and creates an index for a MongoDB object named restaurants, sorted ascending by the field name? ``` var indexCollection = function(db) {return co(function*() {...});}; ``` - [ ] `const results = yield db.table('restaurants').createIndex({"name": 1}, null); return results;` - [ ] `const results = yield db.collection('restaurants').createIndex({"name": 0}, null); return results;` - [x] `const results = yield db.collection('restaurants').createIndex({"name": 1}, null); return results;` - [ ] `const results = yield db.table('restaurants').createIndex({"name": 0}, null); return results;` # Which Cypher code executes the multiquery block? - [ ] ``` MATCH (c:Company {name: 'Neo4j'}) RETURN c, MATCH (p:Person) WHERE p.name = 'Jennifer' RETURN p, MATCH (t:Technology)-[:LIKES]-(a:Person {name: 'Jennifer'}) RETURN t.type; ``` - [ ] ``` MATCH (c:Company {name: 'Neo4j'}) RETURN c, MATCH (p:Person) WHERE p.name = 'Jennifer' RETURN p, MATCH (t:Technology)-[:LIKES]-(a:Person {name: 'Jennifer'}) RETURN t.type ``` - [ ] ``` MATCH (c:Company {name: 'Neo4j'}) RETURN c AND MATCH (p:Person) WHERE p.name = 'Jennifer' RETURN p, AND MATCH (t:Technology)-[:LIKES]-(a:Person {name: 'Jennifer'}) RETURN t.type; ``` - [ ] ``` MATCH (c:Company {name: 'Neo4j'}) RETURN c;MATCH (p:Person) WHERE p.name = 'Jennifer' RETURN p; MATCH (t:Technology)-[:LIKES]-(a:Person {name: 'Jennifer'}) RETURN t.type; ``` # You need to create a scalable database that supports immutable writes. What do you use? - [x] A ledger database - [ ] A graph database - [ ] A key-value database - [ ] A columnstore database # You need to create a data store for the catalog for your new ecommerce application. Your company is a startup, so the catalog schema may evolve. Which do you choose? - [ ] Neo4j - [ ] Redis - [ ] MySQL - [x] MongoDB # You need to select a NoSQL database for heavy aggregate query workloads. Which type do you choose? - [ ] graph - [ ] key-value - [ ] document - [x] columnstore # You need to select a columnstore database that enforce built-in data types. You want to add indexes to improve performance for known workloads. Which do you choose? - [ ] Cassandra - [ ] Bigtable - [x] Redis - [ ] HBase # In DynamoDB, the partition key and sort key are also known as which type of attributes? - [ ] range, hash - [ ] primary, range - [x] hash, range - [ ] range, secondary # What is a popular, open-source key-value store database? - [ ] MongoDB - [x] Redis - [ ] MySQL - [ ] Cassandra # You need to create a scalable database to store and query JSON data. What do you use? - [ ] relational DB - [x] document DB - [ ] graph DB - [ ] ledger DB [store and query JSON](https://aws.amazon.com/nosql/document/#:~:text=The%20document%20database%20defined,use%20in%20their%20application%20code.)