Postgresql PGCES-02 Exam Prep
PGCES-02 PostgreSQL CE 8 Silver (Page 6 )

• Domeny tworza restrykcjony razem z typem. Wykorzystujesz je w kolumnach, aby miec spójna walidacje danych w wielu miejscach.
• To nie jest pelny niestandardowy typ z wlasnym input/output funkcjonowaniem. Aby stworzyc typ z wlasnym I/O i operacjami, uzylbys CREATE TYPE (lub rozszerzen w C). Domeny to uproszczona forma ograniczen na istniejacy typ.

• CREATE DOMAIN positive_int AS integer NOT NULL CHECK (VALUE > 0);
• CREATE TABLE orders (id serial, qty positive_int);

• latwo wymuszaja wspólne reguly dla wielu kolumn/naglówków,
• zmiana regul w jednym miejscu (domena) automatycznie wplywa na wszystkie kolumny ja uzywajace.

• Co to znaczy: transakcje zachowuja sie tak, jakby byly wykonywane jeden po drugim. Dzieki temu nie ma brudnych odczytów, niepowtarzalnych odczytów ani phantom reads.

• Implementacja: PostgreSQL uzywa SSI (Serializable Snapshot Isolation). W praktyce oznacza to, ze jesli wykryje konflikt miedzy transakcjami, jedna z nich zostanie zakonczona bledem “serialization failure” i trzeba ja ponowic.

• Zalózmy tabele orders(customer_id int, amount int).

• Transakcja T1:

• Transakcja T2, równoczesnie:

• T1 ponownie wykonuje to zapytanie:

• vSmart controls the overlay control plane. It uses OMP to exchange routing information, distribute policies, and determine how WAN Edge devices reach one another.
• vManage is the centralized management and configuration platform.
• vBond is the orchestrator. It helps devices authenticate, discover controllers, and traverse NAT during onboarding.
• APIC-EM is not the SD-WAN control-plane component described here.

1. Which host originated the infection

1. Which remaining hosts are infected

1. The sender hashes the original message and sends the message plus its hash.
2. The receiver applies the same hashing algorithm to the received message.
3. The receiver compares the newly calculated hash with the sender’s hash.
4. Matching values indicate that the message was not altered in transit.

• A binary image is not the normal description of a hash result.
• Using a different algorithm produces a different type of digest, so the values cannot be directly compared.
• Hashing verifies integrity, but by itself does not prove who sent the message. Digital signatures or MACs address authentication and integrity together.

• Compare each server’s drive specifications and performance data.
• Identify the drive that is faulty, slow, or mismatched.
• Replace it with a drive that matches the required interface, capacity, and performance characteristics.
• Avoid selecting a slower drive, because storage performance can bottleneck the entire server.
• In a redundant array, use a compatible replacement so rebuilding does not create unnecessary performance degradation.

• Azure Resource Manager (ARM) templates
• Or, in newer Azure terminology, Bicep files

• R-squared: Typically used for regression, not classification.
• RMSE: Measures prediction error for continuous numerical values, so it is not the best fit here.
• Learning rate: A training hyperparameter that controls how quickly the model updates its weights; it is not an evaluation metric.

• A. Modify CommunitiesSelfRegController

• C. Configure Communities registration to use a custom Visualforce page

• B. Modify the self-registration trigger — There is no standard “self-registration trigger” intended for this configuration. The registration logic is handled by the Visualforce controller.
• D. Configure a custom Apex controller — The standard approach is to modify the provided CommunitiesSelfRegController, rather than simply selecting a separate controller configuration.

• 800 devices ? a scalable, centralized solution is needed.
• Four hardware/vendor classes ? the tool must handle different drivers and images.
• Two user groups ? it should allow different configurations for each group.
• “Distribute custom images” ? an imaging/deployment tool is required, not just a file-copy utility.

• Default network device credentials: More associated with external attackers or poor device configuration.
• Spear phishing emails: Commonly used to compromise users, but less characteristic of an insider who already has access.
• Typosquatting and impersonation: Primarily social-engineering techniques aimed at deceiving users.
• Unidentified removable devices: Provide a direct way to transfer data outside the organization and may bypass network monitoring.

• B: Moving the task may affect the critical path and should not be done before evaluating the planned response and impacts.
• C: Excluding a required task is not appropriate without formal analysis and stakeholder approval.
• D: Lessons learned and the risk log should be updated, but only after or alongside managing the immediate issue; updating them is not the first action.

json 
{ 
  "Effect": "Deny", 
  "NotAction": [ 
    "iam:*", 
    "route53:*", 
    "cloudfront:*", 
    "support:*" 
  ], 
  "Resource": "*", 
  "Condition": { 
    "StringNotEquals": { 
      "aws:RequestedRegion": "eu-west-1" 
    } 
  } 
}

• SCPs set maximum permissions; they do not grant permissions. The default SCP allows actions, so the restriction must be an explicit Deny.
• aws:RequestedRegion checks the Region targeted by an API request.
• StringNotEquals: eu-west-1 denies requests directed to every other Region.
• NotAction allows designated global services to remain usable because they do not operate in a single AWS Region.
• Attaching the SCP to the OU makes it apply to existing accounts and accounts later added to that OU.

• principal represents the source or initiating system.
• principal.port is the source port.
• target represents the destination system.
• target.port is the destination port.

text 
principal.port = 5555

• network.ApplicationProtocol = HTTP identifies HTTP traffic but not the backdoor specifically.
• target.port = 5555 finds traffic going to port 5555, rather than originating from it.
• network.ip_protocol = TCP is too broad because many services use TCP.

• Azure Resource Manager (ARM) templates define the virtual machines and related Azure resources declaratively. You can deploy the same template repeatedly, ensuring consistent VM sizes, networking, storage, extensions, and other infrastructure settings.

• PowerShell DSC extension applies and maintains the required Windows configuration inside each VM. DSC is state-based: if a setting changes or becomes incorrect, DSC can bring it back to the desired configuration.

• Azure Pipelines deployment groups organize deployment targets, but they do not primarily enforce ongoing VM configuration.
• Custom Script Extension runs setup scripts, but it is generally less maintainable and does not continuously enforce configuration like DSC.
• Pipeline stage templates reuse pipeline workflow definitions; they do not configure the VMs themselves.

• Have a definite, clear objective (C): Know exactly what you want to communicate. A clear purpose reduces ambiguity and irrelevant information.
• Plan the communication (E): Decide what to say, who needs the information, the appropriate channel and the best timing.
• Seek feedback (F): Check that the receiver understood the message. This could involve asking for confirmation or inviting questions.

• Ask questions (A): Usually associated with the receiver checking or clarifying information, although a sender may use questions in practice.
• Give feedback (B): Feedback is generally the receiver’s response to the sender’s message. The sender’s responsibility here is to seek feedback.
• Consider their contribution (D): This is not a standard sender-focused step in the communication process. The sender should consider the receiver’s needs and perspective, but the wording is less precise than the three recognised actions above.

• A — VARIANT "null" values are not the same as SQL NULL: Correct.

• B — Frequent, single-row DMLs: Incorrect.

• C — Validate data before loading into the target table: Correct.

• D — Use staging tables to manage MERGE statements: Correct.

1. Determine which host was infected first—the originating host.
2. Decide whether each other host is clean or infected based on communication and event logs.

• Compare timestamps and find the earliest suspicious event.
• Look for the host that initiated the malicious connection, file transfer, exploit, or command—not merely a host that later received traffic.
• Follow the timeline through the firewall:

• A host is likely infected if it both receives suspicious activity and then initiates related malicious traffic.
• A host may be clean if the firewall blocked the connection and there is no evidence of execution or follow-on communication.

• Hardware and infrastructure
• System software
• Networks and communications
• Technology platforms and services

• Business Architecture: Defines business strategy, organization, functions, and processes.
• Data Architecture: Defines the structure and management of enterprise data.
• Application Architecture: Describes application systems and how they interact to support business and data processing.

• Identity provider (IdP): Authenticates users and asserts their identity.
• Service provider (SP): The application being accessed—in this case, Salesforce/the employee portal.
• Identity store: A directory that stores user identities, such as Active Directory.
• Authentication store: A system used to validate credentials.

• Espionage: Stealing information for intelligence or competitive purposes.
• Data exfiltration: Unauthorized removal or transfer of data.
• Nation-state attack: A sophisticated attack sponsored by a government.
• Shadow IT: Unapproved technology or access methods used by employees.

sql 
CREATE PROCEDURE dbo.usp_CreateOrder 
AS 
BEGIN 
    SET NOCOUNT ON; 
    SET XACT_ABORT ON; 


    BEGIN TRY 
        BEGIN TRANSACTION; 


        INSERT INTO dbo.Orders (/ columns /) 
        VALUES (/ values /); 


        SET @OrderID = SCOPE_IDENTITY(); 


        COMMIT TRANSACTION; 
    END TRY 
    BEGIN CATCH 
        IF @@TRANCOUNT > 0 
            ROLLBACK TRANSACTION; 


        THROW; 
    END CATCH; 
END;

• BEGIN TRY contains the transactional work.
• SCOPE_IDENTITY() retrieves the identity generated by the INSERT; it belongs after the insert, not as the error-handling logic.
• COMMIT runs only if all statements succeed.
• BEGIN CATCH handles failures.
• IF @@TRANCOUNT > 0 prevents attempting a rollback when no transaction is active.
• ROLLBACK undoes partial changes.
• THROW re-raises the original error with consistent details for the application.
• SET XACT_ABORT ON ensures many run-time errors automatically terminate and roll back the transaction.

1. Modify the database subnet NACL inbound rules to allow traffic from the new web subnet’s CIDR block on the MySQL port (3306).
2. Modify the database subnet NACL outbound rules to allow return traffic to the new web subnet’s CIDR block on the required ephemeral port range.

• Secure: uses encryption, such as HTTPS or SFTP.
• Cross-platform: supported by many languages and operating systems.
• Internet-friendly: designed to communicate across networks, usually using standard Internet protocols.

• JSON/REST over HTTPS — widely supported, secure, and Internet-friendly.
• SOAP over HTTPS — also secure and highly cross-platform, though more heavyweight.
• XML over SFTP — secure file-based exchange, but it is not an API-style interface.

1. Create or verify cost groups

1. Set up the item model group

1. Create the costing version

1. Enter or calculate item costs

1. Activate the standard costs

• Low usage during the first three weeks
• Very high usage during the last week

• High availability: Keeps services running despite failures.
• High latency: Means slow response times; it is not a benefit.
• Load balancing: Distributes traffic across resources but does not specifically address scaling resources up and down.

• User preferences change, so the model must learn from recent data.
• Keeping the existing data helps preserve knowledge of older patterns and provides a broader training distribution.
• Training only on new data can cause catastrophic forgetting and may overfit if the new dataset is small.
• The new data should not automatically be used as the test set, because it is needed for training and the model must still be evaluated on separate, representative data.

• Field name and label
• Data type
• Reference table
• Default value
• Whether the field is mandatory or read-only
• Field attributes and configuration

• A: Labels and translations are handled through documentation and translation-related records.
• C: Table relationships may be represented through reference fields, but this is not the primary description of the Dictionary.
• D: Spell-checking language data is unrelated to the System Dictionary.

• AWS Budgets lets you create a cost or usage budget and configure alerts when actual or forecasted spending reaches a threshold. Notifications can be sent through email or Amazon SNS.
• Amazon CloudWatch can monitor AWS billing metrics and trigger an alarm when estimated charges exceed a specified amount.

• Amazon SQS is a message queue, not a cost-monitoring service.
• Cost Explorer analyzes spending but does not directly provide threshold notifications.
• AWS Cost and Usage Report delivers detailed billing data for analysis; it does not itself send threshold alerts.

• Detect risky sign-ins from unfamiliar or unidentified IP addresses
• Evaluate user or sign-in risk
• Automatically require a password change because of a risky sign-in

• User risk policy: Can require a user to securely change their password when the account may be compromised.
• Sign-in risk policy: Can require MFA or block access based on the risk of a particular sign-in.

• A. Tuning system software: This is a corrective action, not an analysis method. Tuning should be based on measured performance data.
• B. User dissatisfaction reports: Useful as an indicator, but subjective and insufficient for diagnosing the cause.
• D. Off-peak utilization and response time: This may hide problems occurring during peak periods. Performance analysis should cover representative or peak workloads.

• Encryption to preserve confidentiality
• Integrity protection to detect alteration
• Authentication of the server through certificates

• SHA-256: A hashing algorithm; it does not encrypt data for transmission.
• SSL 3.0: Obsolete and insecure. It should not be used.
• AES-256: A strong encryption algorithm, but by itself it does not provide the complete secure communication protocol needed for data in transit.

• 16GB RAM: A 64-bit OS is needed to use more than roughly 4GB effectively, but RAM capacity does not prove the CPU supports 64-bit operation.
• 500GB HDD: Storage capacity has no bearing on OS architecture.
• 1Gbps Ethernet: Network speed is unrelated to CPU architecture.

• Online payment fraud
• Account takeover
• Fake account creation
• Suspicious transactions

• Honeypots: Decoy systems or services made to attract attackers. Legitimate users should not interact with them, so activity there is a strong indicator of malicious behavior.
• DNS sinkholes: Redirect requests for known malicious domains to a controlled internal system. This can reveal infected hosts attempting to contact command-and-control infrastructure.

• Tokenization: Replaces sensitive data with non-sensitive tokens.
• CI/CD: Automates software development, testing, and deployment.
• Threat modeling: Identifies and analyzes potential threats before or during system design.
• Data obfuscation: Makes data harder to understand or interpret.

• You can configure different pre-shared keys for different device groups.
• All cameras could use one key.
• All scanners could use another key.
• Each key can be associated with an appropriate role or access policy.

• Data Category Groups e categorias;
• Visibilidade dessas categorias para perfis ou permission sets.

• B e C: regras de compartilhamento não são o mecanismo apropriado para restringir resultados de busca do Knowledge por divisão.
• D: a role hierarchy não é o mecanismo principal para controlar a visibilidade de categorias do Knowledge. Além disso, a configuração correta é atribuir visibilidade a perfis ou permission sets.

• Restarting the device: May fix software glitches, but would not usually make cable orientation matter.
• Swollen battery: A safety concern, but it would not typically cause recognition only in one cable orientation.
• Failing cable: Possible, but less likely because the problem occurs with this particular device and not other devices of the same type.

• Azure creates a corresponding service principal in Microsoft Entra ID.
• The identity’s lifecycle is tied to the Azure resource.
• If the resource is deleted, Azure automatically deletes the identity.
• Only the associated resource can use that identity to request tokens.
• You can grant the identity permissions to access services such as Key Vault or Storage without storing credentials in code.

• A: Person Accounts cannot be merged directly with standard Contact records.
• C: There is no Account Setup option that automatically merges Person Account duplicates.
• D: Matching rules and duplicate rules can help identify or prevent duplicates, but they do not automatically merge Person Accounts. Also, relationship considerations do not change the basic merge capability.

text 
interface GigabitEthernet0/0.10 
 encapsulation dot1Q 3

• .10 is the router’s local subinterface number.
• dot1Q 3 identifies the 802.1Q VLAN tag carried on the trunk.

text 
interface GigabitEthernet0/0.3 
 encapsulation dot1Q 3

text 
interface GigabitEthernet0/0.2 
 encapsulation dot1Q 2

• s3:GetObject for the relevant objects
• s3:ListBucket if listing is required
• Appropriate bucket and object resource permissions

• B: Making the bucket public is insecure and unnecessary.
• C: Prompt engineering cannot override AWS IAM or encryption permissions.
• D: Data sensitivity does not determine whether the role can access it.

• Valor maior: mais aderência às instruções e aos detalhes descritos.
• Valor menor: mais liberdade criativa e resultados potencialmente mais variados.
• Valor excessivamente alto: pode causar artefatos ou imagens menos naturais.

• Aumentar o número de passos de geração: pode melhorar qualidade e refinamento, mas não é o principal controle de especificidade do prompt.
• MASK_IMAGE_BLACK: relaciona-se ao uso de máscara em geração ou edição de imagens, não à especificidade textual.
• Prompt strength: é mais associado à força do prompt em processos como image-to-image; nesta questão, o parâmetro diretamente ligado à aderência textual é o CFG scale.

Simple explanation

• The Azure VPN gateway to connect to
• Authentication settings
• Routes for networks that the client can access

• Create a record-triggered Flow on Opportunity.
• Run it when the record is created or updated.
• Add entry criteria such as Probability > 50%.
• Use Create Records to create the related Sales Demo Request, populating its Opportunity lookup.

• Apex Trigger: Possible, but unnecessary custom code for a straightforward automation requirement.
• Workflow Rule: Cannot create a related custom record.
• Process Builder: Could create a record, but Flow is Salesforce’s preferred and more capable declarative automation tool.

• B — Reviewing the strategy: Usually performed by a security steering committee or other governance body.
• C — Communicating the strategy: The security manager may help communicate it, but communication is not the primary governance responsibility tested here.
• D — Approving the strategy: Approval belongs to executive management or the appropriate governing authority, not the person who develops it.

• Espionage: Stealing confidential information, often for a competitor or government.
• Data exfiltration: Unauthorized transfer of data outside the organization. This could occur, but the question focuses on using unapproved access methods.
• Nation-state attack: An attack sponsored or conducted by a government.
• Shadow IT: Employees using technology or access methods outside the organization’s approved security controls.

• SQL injection
• Cross-site scripting (XSS)
• Malicious or malformed web requests
• Some application-layer abuse

• Layer 4 firewall: Filters based mainly on IP addresses, ports, and connections; it lacks detailed web-request inspection.
• NGFW: Provides broader network security, but a WAF is more specialized for protecting web applications.
• UTM: Combines multiple security functions, but it is not necessarily optimized for web-application protection.

• Data loss prevention (DLP): Helps detect or prevent sensitive data from being copied or transmitted, but it does not primarily protect a stolen laptop’s stored data.
• Operating system hardening: Reduces vulnerabilities and attack surface but does not encrypt files if the device is stolen.
• Boot security: Helps ensure that only trusted software starts, but it does not fully protect the drive if an attacker accesses it offline.

• Guiding principles
• Governance
• Service value chain
• Practices
• Continual improvement

• Guiding principles: Recommendations that guide decisions and actions; they do not describe the entire system.
• Four dimensions: Perspectives used to ensure a balanced approach to service management.
• Service relationship: Describes cooperation between a service provider and service consumer, rather than the whole value-creation system.