Which type of query optimization technique focuses on reducing the number of rows to be scanned in a database query?
- Indexing
- Partitioning
- Predicate Pushdown
- Projection Pushdown
Predicate Pushdown is a query optimization technique that focuses on reducing the number of rows to be scanned in a database query. It involves pushing down the predicates (conditions) from the outer query into the inner query, thereby filtering the rows early in the query execution process. This helps in improving query performance by minimizing the amount of data that needs to be processed.
SQL injection is a type of security vulnerability that occurs when an attacker can manipulate ____________ statements sent to a database.
- HTTP
- JavaScript
- Query
- SQL
SQL
Advanced test data generation tools often incorporate _________ algorithms to generate complex and realistic data scenarios.
- Genetic
- Iterative
- Random
- Sorting
Advanced test data generation tools often use genetic algorithms to generate complex and realistic data scenarios by mimicking natural selection processes, producing diverse and representative datasets.
____________ testing is performed to assess the database's ability to handle concurrent user requests.
- Load
- Performance
- Scalability
- Stress
Load testing evaluates the system's performance under normal and expected peak load conditions, including assessing the database's concurrent user handling.
In SQL, the "TRY...CATCH" block is used to handle ____________ that may occur during query execution.
- Compilation errors
- Logical errors
- Runtime errors
- Syntax
The "TRY...CATCH" block in SQL is used to handle runtime errors that may occur during query execution. This includes errors such as divide by zero, arithmetic overflow, and so on. The block allows for graceful handling of exceptions, enabling the program to continue executing despite encountering an error.
Database administrators often use monitoring tools to set ____________ that trigger alerts when predefined thresholds are exceeded.
- Constraints
- Indexes
- Queries
- Triggers
Monitoring tools such as triggers enable database administrators to automate the process of monitoring critical thresholds in databases. When specified conditions are met, these triggers can initiate actions like sending alerts, logging events, or executing scripts, allowing administrators to promptly address potential issues before they escalate.
You are responsible for database security in a healthcare organization. A database administrator mistakenly granted read access to sensitive patient records to a non-privileged user. What action should you take to rectify this situation?
- Conduct an audit to identify any other unauthorized accesses and revoke them.
- Implement role-based access control to prevent such incidents in the future.
- Inform the database administrator about the mistake and request them to rectify it.
- Revoke the non-privileged user's read access immediately.
The correct action to rectify the situation is to revoke the non-privileged user's read access immediately. This ensures that unauthorized individuals cannot view sensitive patient records. Informing the database administrator and conducting an audit are necessary steps, but the immediate action should be to remove the unauthorized access. Implementing role-based access control is a preventive measure for the future but does not address the current issue directly.
What is data profiling in ETL testing, and why is it important?
- Analyzing data to understand its structure and content
- Extracting data from various sources
- Loading data into the target system
- Validating data consistency
Data profiling in ETL testing refers to the process of analyzing data to understand its structure, content, relationships, and quality characteristics. It involves examining data patterns, distributions, and anomalies to identify issues such as missing values, outliers, duplicates, or inconsistencies. Data profiling helps testers and developers gain insights into the data and assess its suitability for the ETL process. It is important because it helps identify potential data quality issues early in the ETL lifecycle, enabling organizations to improve data accuracy, integrity, and reliability.
Testers often rely on database testing tools to generate ________ SQL queries for testing.
- Random
- Complex
- Optimized
- Targeted
Database testing tools assist testers in creating targeted SQL queries tailored to specific testing objectives. Option 4, "Targeted," accurately represents the purpose of generating SQL queries in testing scenarios.
Scenario: In an ETL process, you find that certain records in the target database are missing compared to the source. What kind of data validation problem does this indicate?
- Data Accuracy Issue
- Data Completeness Issue
- Data Consistency Issue
- Data Integrity Issue
This indicates a data completeness issue. Data completeness refers to ensuring that all expected data is present and available. In this case, the absence of certain records in the target database suggests that the ETL process did not properly transfer all the data from the source to the target.