A financial institution is setting up an in-memory data warehouse for real-time fraud detection. They are concerned about the potential loss of data in case of a system crash. What should be their primary consideration when setting up this system?
- Data Compression
- Data Encryption
- Data Persistence
- Data Redundancy
In a real-time data warehouse for tasks like fraud detection, ensuring data persistence is crucial. Data persistence mechanisms ensure that data is not lost in case of system crashes, making it essential for maintaining data integrity in critical financial applications.
Which of the following is a benefit of scalability in system design?
- Decreased Redundancy
- Increased Performance
- Limited Adaptability
- Reduced Initial Cost
Scalability in system design allows a system to handle increased workloads without compromising performance. It enables the system to grow or shrink as needed, which is particularly important in dynamic IT environments and for accommodating changes in user demand.
Which type of data load involves processing only the new or changed records since the last load?
- Bulk Load
- Full Load
- Incremental Load
- Reload
An incremental load in data warehousing involves processing only the new or changed records since the last load. This method is more efficient and reduces the processing time compared to a full load because it targets specific data changes rather than reprocessing all data.
Which of the following refers to the ability of a system to handle increasing amounts of work by adding resources to the system?
- Backward Compatibility
- Latency
- Scalability
- Security
Scalability refers to a system's ability to handle increasing workloads by adding resources, such as servers or storage, without compromising performance. This is a crucial concept in data warehousing, as the system should be able to adapt to growing data volumes.
What is the primary purpose of indexing in a data warehouse?
- Accelerating data loading
- Enhancing data security
- Improving query performance
- Reducing storage costs
Indexing in a data warehouse primarily serves to enhance query performance. By creating indexes on key columns, the database system can quickly locate and retrieve relevant data, making query execution more efficient.
In the context of data warehouse performance tuning, what does "query optimization" typically refer to?
- Enhancing database security
- Improving the efficiency of SQL queries
- Reducing the number of queries
- Streamlining data loading processes
Query optimization in data warehouse performance tuning refers to the process of improving the efficiency of SQL queries. This includes techniques like indexing, query rewriting, and choosing the appropriate execution plans to make queries run faster and consume fewer resources. It plays a crucial role in ensuring the data warehouse operates smoothly and delivers timely insights.
Which data warehousing component provides an abstraction layer that sits between the physical database and the user, ensuring that the data accessed is consistent and accurate?
- Data Mining Tools
- Data Staging Area
- Data Warehouse Manager
- Data Warehouse Metadata
Data Warehouse Metadata is a crucial component that provides an abstraction layer between the physical database and users. It stores information about data sources, data transformations, and data quality, ensuring consistent and accurate data access for users.
In a data model, what does a "measure" typically represent?
- A category of data
- A descriptive label
- A numeric value used for calculations
- A unit of weight
In a data model, a "measure" typically represents a numeric value used for calculations, such as quantities, amounts, or values that can be analyzed and aggregated to gain insights and make data-driven decisions. Measures are key components in data analysis and reporting.
In a distributed data warehousing environment, which strategy involves storing copies of data or aggregations of data in multiple locations?
- Data Deduplication
- Data Fragmentation
- Data Normalization
- Data Replication
In a distributed data warehousing environment, data replication is a strategy that involves storing copies of data or aggregations in multiple locations. This strategy enhances data availability and fault tolerance across the distributed system.
An e-commerce business wants to analyze their sales data. They have facts like "total sales" and "number of items sold" and dimensions like "time," "product," and "customer." In a star schema, how should these tables be related?
- All dimension tables directly connected to the fact table
- Dimension tables connected in a hierarchy
- Each dimension table connected to all other dimension tables
- No relationships between tables
In a star schema, all dimension tables are directly connected to the fact table, which represents the center of the schema. This design simplifies queries and ensures quick access to data for analytical purposes.