Sophia __ Welcome milestone 3 test

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Southern New Hampshire University *

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CS-210

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Information Systems

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Feb 20, 2024

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1 16/21 that's 76% RETAKE 16 questions were answered correctly . 5 questions were answered incorrectly . In each milestone, you may want or need to use the database and query tool to answer some of the questions. We suggest you open the tool in another browser tab while you are working on this assessment. https://postgres.sophia.org/ Consider the following scenario: 1. Update ROLLBACK 2. Insert 3. Insert COMMIT 4. Delete 5. Update COMMIT In this scenario, which statements would be saved to the database, assuming these are all in a single transaction? 1, 2, 3, 4, 5 4, 5 UNIT 3 — MILESTONE 3 16/21
CONCEPT COMMIT and ROLLBACK to Manage Changes 2 RATIONALE In a transaction, if a ROLLBACK statement is run, all statements up to the prior COMMIT or ROLLBACK statement will be reverted. If a COMMIT statement is run, all statements up to the prior ROLLBACK or COMMIT statement will be saved. Report an issue with this question In each milestone, you may want or need to use the database and query tool to answer some of the questions. We suggest you open the tool in another browser tab while you are working on this assessment. https://postgres.sophia.org/ Which of the following scenarios reflects the atomicity property? 2, 3, 4, 5 2, 3 1. The product quantity starts at 200. 2. Transaction 1 runs to read the quantity of the product to be updated. 3. Transaction 2 runs in parallel to read the quantity of the product to be updated. UNIT 3 — MILESTONE 3 16/21
4. Transaction 1 updates the product quantity to reduce it by 100. 5. Transaction 2 updates the product quantity to reduce it by 5. 6. The product quantity ends at 195. 1. A fairly large update to the products table. 2. The update is saved to the logs. 3. The update starts to then save to the disk. 4. The system fails midway through. 5. When the system starts back up, the committed transactions that haven't been written to disk are written. 1. User 1 has $500 in their online account. 2. User 2 has $300 in their online account. 3. User 1 sends user 2 $100. 4. User 1 has $400 in their account. 5. User 2 has $300 in their account. 6. The transaction is reverted. 1. Transaction 1 reads a product's cost which is set at $100. 2. Transaction 1 updates the product to set the price to $90. UNIT 3 — MILESTONE 3 16/21
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CONCEPT Atomicity 3 RATIONALE Atomicity requires that all SQL requests in a transaction should be fully completed and if not, the entire transaction should be aborted. The transaction should be viewed as a single logical unit of work that is indivisible. Report an issue with this question In each milestone, you may want or need to use the database and query tool to answer some of the questions. We suggest you open the tool in another browser tab while you are working on this assessment. https://postgres.sophia.org/ Which of the following statements would create a role named database_admin which gives them the ability to create databases? 3. Transaction 2 reads the same product's cost and sees $100. 4. Transaction 1 commits the cost. 5. Transaction 3 reads the same product's cost and sees $90. CREATE ROLE database_admin CREATEROLE; UNIT 3 — MILESTONE 3 16/21
CONCEPT CREATE ROLE to Create Groups 4 RATIONALE Common mistakes when creating roles are using quotes around the role name, not setting the correct role privileges, and using the incorrect syntax. Report an issue with this question In each milestone, you may want or need to use the database and query tool to answer some of the questions. We suggest you open the tool in another browser tab while you are working on this assessment. https://postgres.sophia.org/ What is unique about a superuser compared to a user? CREATE ROLE database_admin NOINHERIT; CREATE ROLE database_admin INHERIT; CREATE ROLE database_admin CREATEDB; UNIT 3 — MILESTONE 3 16/21
CONCEPT Superusers 5 RATIONALE A superuser role is one that is able to bypass all permission checks so they are not even verified. Report an issue with this question In each milestone, you may want or need to use the database and query tool to answer some of the questions. We suggest you open the tool in another browser tab while you are working on this assessment. https://postgres.sophia.org/ A superuser has their permissions checked but passes all tests. A superuser has administrative privileges that users can't have. A superuser can bypass all permission checks. A superuser is the same as a regular user but with all permissions granted. UNIT 3 — MILESTONE 3 16/21
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Which of the following statements represents a correctly structured transaction? BEGIN UPDATE customer SET postal_code = '33433' WHERE customer_id = 22 UPDATE customer SET postal_code = '10789' WHERE city = 'Berlin' UPDATE customer SET company = 'Humor Inc.' WHERE city = 'Prague' COMMIT UPDATE customer SET postal_code = '33433' WHERE customer_id = 22; UPDATE customer SET postal_code = '10789' WHERE city = 'Berlin'; UPDATE customer SET company = 'Humor Inc.' WHERE city = 'Prague'; COMMIT; UNIT 3 — MILESTONE 3 16/21
CONCEPT Transactions RATIONALE Common mistakes with a transaction include missing a semicolon (;) after BEGIN or after the COMMIT at the end of the statement, not having the COMMIT at the end of the statement, and not including BEGIN at the start of the statement. Report an issue with this question BEGIN; UPDATE customer SET postal_code = '33433' WHERE customer_id = 22; UPDATE customer SET postal_code = '10789' WHERE city = 'Berlin'; UPDATE customer SET company = 'Humor Inc.' WHERE city = 'Prague'; COMMIT; BEGIN; COMMIT; UPDATE customer SET postal_code = '33433' WHERE customer_id = 22; UPDATE customer SET postal_code = '10789' WHERE city = 'Berlin'; UPDATE customer SET company = 'Humor Inc.' WHERE city = 'Prague'; UNIT 3 — MILESTONE 3 16/21
6 CONCEPT DROP INDEX to Remove Indexes In each milestone, you may want or need to use the database and query tool to answer some of the questions. We suggest you open the tool in another browser tab while you are working on this assessment. https://postgres.sophia.org/ Which of the following DROP INDEX statements would refuse to drop the index if any objects depend on it? RATIONALE Common mistakes when dropping an index include not including the correct index name, using the incorrect syntax, and not using the right parameters based on the requirements. Using IF EXISTS will not throw an error if the index does not exist. CONCURRENTLY will drop the index without locking concurrent select, insert, updates and deletes. CASCADE will automatically drop objects that depend on the index. RESTRICT will refuse to drop the index if any objects depend on it. This is set by default. DROP INDEX IF EXISTS myindex; DROP INDEX myindex RESTRICT; DROP INDEX CONCURRENTLY myindex; DROP INDEX myindex CASCADE; UNIT 3 — MILESTONE 3 16/21
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7 CONCEPT Application Security Report an issue with this question In each milestone, you may want or need to use the database and query tool to answer some of the questions. We suggest you open the tool in another browser tab while you are working on this assessment. https://postgres.sophia.org/ Using which type of process between the user input and dynamically created statements can help reduce the number of SQL injection attacks? RATIONALE By filtering the user input, we can ensure that we're checking for any special characters that should not be included. Report an issue with this question Coding Filtering Posting Construction UNIT 3 — MILESTONE 3 16/21
8 In each milestone, you may want or need to use the database and query tool to answer some of the questions. We suggest you open the tool in another browser tab while you are working on this assessment. https://postgres.sophia.org/ Which is an advantage of both the command line and the GUI? RATIONALE With the command line, you have more flexibility with all of the parameters to backup and restore the database. You're able to pipe together commands to be able to backup and restore data into different databases and have more control. With the GUI, you have more options to select from, but all of them are limited to the functionality that has been implemented. Both types do allow us to continue to restore a database or stop if there's an error. We're also able to encode the backup files or backup the data, schema, or both using either option. We can restore a remote database. We can use any parameters without limitation. We can encode the backup file to another format. We can backup multiple databases at once. UNIT 3 — MILESTONE 3 16/21
CONCEPT Backups: Command Line vs. GUI 9 Report an issue with this question In each milestone, you may want or need to use the database and query tool to answer some of the questions. We suggest you open the tool in another browser tab while you are working on this assessment. https://postgres.sophia.org/ Which of the following scenarios reflect the consistency property? 1. A fairly large transaction is run to import new customers. 2. The import is saved to the logs. 3. The import starts to then save to the disk. 4. The disk fails midway through the update. 5. A new disk replaces the failed disk. 6. The backup is applied and the saving of the data is run from the logs. 1. Jeff checks his user profile and sees his email address is set to jeff@gmail.com. 2. Jeff changes his email to set it to jeff@outlook.com but does not click on save yet. 3. A customer rep checks into UNIT 3 — MILESTONE 3 16/21
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RATIONALE The consistency property ensures that a transaction takes the database from one consistent state to another consistent state. If any transaction part violates an integrity constraint, the entire transaction should be rolled back. Jeff's account and sees jeff@gmail.com. 4. Jeff clicks on save. 5. Another customer rep checks Jeff's account and sees jeff@outlook.com. 1. A vendor has 5 orders available. 2. A customer attempts to purchase all 5. 3. The system deducts it from the vendor and adds it to the customer. 4. The vendor now has 0 orders available. 5. The customer has 0 orders purchased. 5. The transaction is saved. 1. User 1 has $500 in their online account. 2. User 2 has $300 in their online account. 3. User 1 sends user 2 $100. 4. User 1 has $400 in their account. 5. User 2 has $300 in their account. 6. The transaction is reverted. UNIT 3 — MILESTONE 3 16/21
CONCEPT Consistency 10 Report an issue with this question In each milestone, you may want or need to use the database and query tool to answer some of the questions. We suggest you open the tool in another browser tab while you are working on this assessment. https://postgres.sophia.org/ Which of the following statements would dump ONLY the table customer from the mydatabase database to backup.sql? RATIONALE Common mistakes when backing up a database using the command line include using the wrong file redirect operator, pg_dump -a customer mydatabase > backup.sql pg_dump mydatabase customer > backup.sql pg_dump -t customer > backup.sql pg_dump -t customer mydatabase > backup.sql UNIT 3 — MILESTONE 3 16/21
CONCEPT Create a Backup 11 using the incorrect syntax, not using the right order of statements, and not including the command line options. Report an issue with this question In each milestone, you may want or need to use the database and query tool to answer some of the questions. We suggest you open the tool in another browser tab while you are working on this assessment. https://postgres.sophia.org/ Which of the following properties are specific to the durability property? All SQL requests of a transaction must be completed; if not, the transaction must be aborted. Data used in one transaction cannot be used in another transaction until the first transaction is completed. Once transaction changes are done and saved, they cannot be lost. When a transaction is completed, the database must be in a UNIT 3 — MILESTONE 3 16/21
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CONCEPT ACID Properties 12 RATIONALE The durability property ensures that once a transaction is done and committed, the changes cannot be undone or lost, even if there is a system failure. Report an issue with this question In each milestone, you may want or need to use the database and query tool to answer some of the questions. We suggest you open the tool in another browser tab while you are working on this assessment. https://postgres.sophia.org/ Which of the following operators will attempt to use a hash or b- tree index? consistent state. && >> @> = UNIT 3 — MILESTONE 3 16/21
CONCEPT Index Overview 13 RATIONALE By default, the b-tree index will be used if one of the following operators are used: <, <=, =, >= or >. The hash index will only be used if it is involved in a = operator. GiST indexes are focused on multiple indexing strategies being used and would be used in other operators. Report an issue with this question In each milestone, you may want or need to use the database and query tool to answer some of the questions. We suggest you open the tool in another browser tab while you are working on this assessment. https://postgres.sophia.org/ Which of the following sequences of statements would ensure that Jerry has the privileges of the roles of sales and associate? CREATE ROLE associate INHERIT; CREATE ROLE sales INHERIT; GRANT sales to jerry; GRANT associate to jerry; CREATE ROLE associate NOINHERIT; CREATE ROLE sales NOINHERIT; GRANT associate to jerry; GRANT associate to sales; UNIT 3 — MILESTONE 3 16/21
CONCEPT GRANT to Assign Users 14 RATIONALE Common mistakes when assigning roles include not identifying which roles have INHERIT or NOINHERIT privileges, and not ensuring that the user has all of the roles allocated to the user. Report an issue with this question In each milestone, you may want or need to use the database and query tool to answer some of the questions. We suggest you open the tool in another browser tab while you are working on this assessment. https://postgres.sophia.org/ In which of the following cases would it make the most sense to use a hash index? CREATE ROLE associate NOINHERIT; CREATE ROLE sales INHERIT; GRANT sales to jerry; GRANT associate to sales; CREATE ROLE associate NOINHERIT; CREATE ROLE sales NOINHERIT; GRANT sales to jerry; GRANT associate to sales; UNIT 3 — MILESTONE 3 16/21
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CONCEPT Hash Index 15 RATIONALE Hash indexes can only be used when we have equality comparisons. It does not work well with wild cards or any ranges. Report an issue with this question In each milestone, you may want or need to use the database and query tool to answer some of the questions. We suggest you open the tool in another browser tab while you are working on this assessment. SELECT * FROM customer WHERE customer_id > 10 AND customer_id < 20; SELECT * FROM track WHERE media_type_id = 1; SELECT * FROM album WHERE artist_id < 5; SELECT * FROM employee WHERE address LIKE '%i%'; UNIT 3 — MILESTONE 3 16/21
https://postgres.sophia.org/ Which of the following scenarios reflects the durability property? 1. Tiffany has updated a customer's address while on the phone with them. 2. The server restarted after Tiffany clicked on save. 3. When the server comes back up, Tiffany was able to verify that the address was updated. 1. In the library database, there are 50 books available. 2. Billy has checked and there are 50 books. 3. Sam has checked and there are 50 books. 4. Billy has taken out 5 books. 5. The library system informs Sam of the update and Sam now checks that there are 45 books. 6. Sam checks out 10 books. 7. There are now 35 books in the library database. 1. A user attempts to do a product transfer between companies. 2. The quantity of the product is moved from the first company. 3. Only once the product is verified to have been deducted, the quantity is moved to the second company. 4. Verification is done and UNIT 3 — MILESTONE 3 16/21
CONCEPT Durability 16 RATIONALE The durability property ensures that once a transaction is done and committed, the changes cannot be undone or lost even if there is system failure. Report an issue with this question In each milestone, you may want or need to use the database and query tool to answer some of the questions. We suggest you open the tool in another browser tab while you are working on this assessment. https://postgres.sophia.org/ identifies that the total amounts before and after the transactions are not maintained. 5. The transaction is reverted. 1. In the flower database, there are 50 flowers available. 2. Reese has checked and there are 50 flowers. 3. Reese has attempted to take out 5 flowers. 4. Which trying to take them out, there was an error in trying to dispense. 5. While checking, there are still 50 flowers available in the system. UNIT 3 — MILESTONE 3 16/21
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CONCEPT Restore from Backup 17 Which of the following statements would only restore the schema, but not the data, of the database mydatabase from backup.sql? RATIONALE Common mistakes when backing up a database using the command line include using the wrong file redirect operator, using the incorrect syntax, not using the right order of statements, and not including the command line options. Report an issue with this question In each milestone, you may want or need to use the database and query tool to answer some of the questions. We suggest you open the tool in another browser tab while you are working on pg_restore -s mydatabase < backup.sql pg_restore -a mydatabase < backup.sql pg_restore -d mydatabase < backup.sql pg_restore mydatabase < backup.sql UNIT 3 — MILESTONE 3 16/21
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CONCEPT B-Tree Index this assessment. https://postgres.sophia.org/ In which of the following cases would it make the most sense to use a b-tree index? RATIONALE The b-tree index makes the most sense to use when the data is even and balanced. It works best on data types like text, numbers, and timestamps when we compare ranges or content that start with a value. It does not work well with wild cards at the start of a comparison or ranges. SELECT * FROM employee WHERE title LIKE '%IT%'; SELECT * FROM invoice WHERE invoice_id > 10 AND invoice_id < 200; SELECT * FROM customer WHERE email LIKE '%gmail%'; SELECT * FROM customer WHERE fax LIKE '%7070'; UNIT 3 — MILESTONE 3 16/21
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18 Report an issue with this question In each milestone, you may want or need to use the database and query tool to answer some of the questions. We suggest you open the tool in another browser tab while you are working on this assessment. https://postgres.sophia.org/ Which type of backup would require no more than 2 backup sets? RATIONALE Full backups are a full copy of the entire data set. Although they are the best protection, they are time-consuming and quite large to store. Incremental backups only back up the data that has changed since the previous backup, even if it's another incremental backup. These file sizes are the smallest out of the lot. Differential backups are similar to incremental backups, but they start with a full backup and include data Differential and incremental backup Differential and full backup Incremental and full backup Full backup and nightly backup UNIT 3 — MILESTONE 3 16/21
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CONCEPT Backup Methods 19 since the prior full backup. At most, there are only 2 backups to restore from. Report an issue with this question In each milestone, you may want or need to use the database and query tool to answer some of the questions. We suggest you open the tool in another browser tab while you are working on this assessment. https://postgres.sophia.org/ Which of the following statements will grant update permissions on the customer table to all users? RATIONALE GRANT UPDATE ON customer TO ALL; GRANT UPDATE ON customer TO public; GRANT UPDATE ON public to customer; GRANT UPDATE ON 'customer' TO 'public'; UNIT 3 — MILESTONE 3 16/21
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CONCEPT GRANT to Assign Privileges 20 Common mistakes when granting privileges to roles include using quotes around the table or role name, not using commas between privileges, including the incorrect privileges, and using the incorrect syntax. Report an issue with this question In each milestone, you may want or need to use the database and query tool to answer some of the questions. We suggest you open the tool in another browser tab while you are working on this assessment. https://postgres.sophia.org/ Which of the following statements would create a user login role named temporary_user with the password set as changeme that is valid until 2025-05-01? CREATE ROLE temporary_user LOGIN PASSWORD 'changeme' VALID UNTIL '2025-05-01' CREATE ROLE temporary_user LOGIN PASSWORD 'changeme' EXPIRES '2025-05-01' UNIT 3 — MILESTONE 3 16/21
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CONCEPT CREATE USER/ROLE to Add Users 21 RATIONALE Common mistakes when creating a user include adding quotes to the username, forgetting to add quotes to the password, incorrectly setting the additional parameters, and using the incorrect syntax. Report an issue with this question In each milestone, you may want or need to use the database and query tool to answer some of the questions. We suggest you open the tool in another browser tab while you are working on this assessment. https://postgres.sophia.org/ Which of the following scenarios reflects the isolation property? CREATE ROLE temporary_user LOGIN PASSWORD changeme VALID UNTIL 2025-05-01 CREATE ROLE temporary_user LOGIN VALID UNTIL '2025-05-01' PASSWORD 'changeme' 1. A vendor has 5 orders available. UNIT 3 — MILESTONE 3 16/21
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2. A customer attempts to purchase all 5. 3. The system deducts it from the vendor and adds it to the customer. 4. The vendor now has 0 orders available. 5. The customer has 5 orders purchased. 6. The transaction is saved. 1. User 1 has $500 in their online account. 2. User 2 has $300 in their online account. 3. User 1 sends user 2 $100. 4. User 1 has $400 in their account. 5. User 2 has $300 in their account. 6. The transaction is reverted. 1. A fairly large transaction is run to import new customers. 2. The import is saved to the logs. 3. The import starts to then save to the disk. 4. The disk fails midway through the update. 5. A new disk replaces the failed disk. 6. The backup is applied and the saving of the data is run from the logs. 1. Jeff checks his user profile and sees his email address is set to UNIT 3 — MILESTONE 3 16/21
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CONCEPT Isolation RATIONALE The isolation property ensures that the data used in a transaction cannot be used in another transaction until the original transaction is complete with it. This is important when you have multiple users accessing and updating data in the database at the same time. Report an issue with this question jeff@gmail.com. 2. Jeff changes his email to set it to jeff@outlook.com but does not click on save yet. 3. A customer rep checks into Jeff's account and sees jeff@gmail.com. 4. Jeff clicks on save. 5. Another customer rep checks Jeff's account and sees jeff@outlook.com. About Contact Us Privacy Policy Cookie Policy Terms of Use Your Privacy Choices © 2024 SOPHIA Learning, LLC. SOPHIA is a registered trademark of SOPHIA Learning, LLC. UNIT 3 — MILESTONE 3 16/21
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