Computer Knowledge
Database Management Systems
5,543 Questions
Database Management Systems (DBMS) form the core framework for data storage, retrieval, and security in modern software applications. Concepts such as the E-R model, backup planning, SQL integration, and big data architecture are essential for computer knowledge sections. This hub offers a comprehensive set of practice questions to master DBMS fundamentals and advanced database operations.
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Database Management Systems Questions
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BULK insert
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BCP
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DTS
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All the above
D
Correct answer
Explanation
SQL Server provides multiple tools for data import and export: BULK INSERT is a T-SQL command for bulk data loading, BCP (Bulk Copy Program) is a command-line utility, and DTS (Data Transformation Services) is a graphical tool for data transfer and transformation. All three are valid options.
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At least one data mart
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Data that can extracted from numerous internal and external sources
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Near real-time updates
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All of the above.
B
Correct answer
Explanation
The generic two-level data warehouse architecture consists of a central data warehouse that extracts and consolidates data from multiple internal and external sources. Data marts (A) are derived from the warehouse, not part of the core architecture definition, and near real-time updates (C) are not a required feature of the basic architecture.
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System tablespace
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Users tablespace
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Default tablespace for the user
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Default tablespace for system
C
Correct answer
Explanation
When a user creates an object in Oracle without specifying a TABLESPACE clause, Oracle stores the segment in that user's default tablespace. This is a user-specific default, not the system tablespace. Each user can be assigned a specific default tablespace for their objects.
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DBA_SYS_PRIVS
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DBA_COL_PRIVS
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DBA_OBJ_PRIVS
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DBA_TAB_PRIVS
A
Correct answer
Explanation
DBA_SYS_PRIVS provides information about all system privileges granted in the database. The other options are more specific: DBA_COL_PRIVS for column-level privileges, DBA_OBJ_PRIVS for object privileges, and DBA_TAB_PRIVS for table privileges. System privileges are the broadest category of grants.
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You need to have the same hardware.
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The database you mirror to will be in an unused standby state.
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You cannot have automatic failover.
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You need to have at minimum three servers.
B
Correct answer
Explanation
In database mirroring, the mirror database remains in a restoring/standby state and cannot be directly read or written to by users, representing idle capacity. Identical hardware is not strictly mandatory, automatic failover is supported, and a witness server is optional.
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Database Engine Tuning Advisor
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SQL Server Configuration Manager
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Database Maintenance Plan Wizard
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Database Maintenance design surface
C
Correct answer
Explanation
The Database Maintenance Plan Wizard provides a step-by-step interface specifically designed for creating backup and maintenance plans. It is the most appropriate tool for a junior DBA because it simplifies the process of creating a reliable backup strategy. Database Engine Tuning Advisor is for query optimization, and Configuration Manager manages server services.
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At least one data mart
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Data that can extracted from numerous internal and external sources
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Near real-time updates
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All of the above.
D
Correct answer
Explanation
An active data warehouse architecture includes all the listed components: data marts for focused subject areas, data extraction from multiple sources (internal and external), and near real-time update capabilities. These are all essential characteristics of an active data warehouse. The question asks 'which of the following' making 'All of the above' the correct answer.
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Data stored in the various operational systems throughout the organization.
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Current data intended to be the single source for all decision support systems.
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Data stored in one operational system in the organization.
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Data that has been selected and formatted for end-user support applications.
B
Correct answer
Explanation
Reconciled data is current, consistent data that serves as the single, authoritative source for all decision support systems in an organization. It is not the raw data in operational systems (which may be inconsistent), nor is it data formatted for specific end-user applications. The reconciliation process creates this unified, current data source.
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Data in which changes to existing records cause the previous version of the records to be eliminated
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Data in which changes to existing records do not cause the previous version of the records to be eliminated
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Data that are never altered or deleted once they have been added
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Data that are never deleted once they have been added
A
Correct answer
Explanation
Transient data holds only the current state; any update or change to an existing record overwrites and eliminates the previous version. Periodic or historical data retains past versions, while persistent data is characterized by never being altered or deleted after addition.
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A process to reject data from the data warehouse and to create the necessary indexes
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A process to load the data in the data warehouse and to create the necessary indexes
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A process to upgrade the quality of data after it is moved into a data warehouse
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A process to upgrade the quality of data before it is moved into a data warehouse
D
Correct answer
Explanation
Data scrubbing is the process of cleaning and improving data quality BEFORE it is loaded into the data warehouse. It involves correcting errors, standardizing formats, and resolving inconsistencies during the ETL process. Scrubbing happens as part of the transformation phase, not after loading.
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A process to reject data from the data warehouse and to create the necessary indexes
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A process to load the data in the data warehouse and to create the necessary indexes
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A process to upgrade the quality of data after it is moved into a data warehouse
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A process to upgrade the quality of data before it is moved into a data warehouse
B
Correct answer
Explanation
The load and index process involves importing data into the data warehouse (loading) and building the indexes required for query performance. Data quality upgrades are part of cleansing and transformation processes that occur before or during the staging phase rather than the loading phase.
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A process to change data from a detailed level to a summary level
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A process to change data from a summary level to a detailed level
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Joining data from one source into various sources of data
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Separating data from one source into various sources of data
A
Correct answer
Explanation
Data transformation includes converting detailed data into summarized data, such as aggregating transaction-level data into daily or monthly totals. The other options are incorrect: transformation doesn't convert summary to detail, join from one to various sources, or split data arbitrarily. Aggregation is a core transformation function.
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Converts data from one field into multiple fields
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Converts data from multiple fields into one field
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Converts data from multiple fields into multiple fields
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All of the above
D
Correct answer
Explanation
A multifield transformation (like Normalizer) can perform all three patterns: splitting one field into many (parsing), combining multiple fields into one (concatenation/aggregation), and mapping multiple fields to multiple fields (complex restructuring). Informatica's Normalizer is the classic multifield transformation.
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Many-to-many
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One-to-one
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One-to-many
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All of the above.
C
Correct answer
Explanation
In a star schema, each dimension table relates to the fact table in a one-to-many relationship - one dimension record (like Product ID) links to many fact table records (transactions). The dimension is the 'one' side, facts are the 'many' side. Many-to-many would require a bridge table, and one-to-one is atypical in dimensional modeling.
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Completely demoralized
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Partially demoralized
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Completely normalized
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Partially normalized
C
Correct answer
Explanation
Fact tables are typically completely normalized (to 3NF) in dimensional modeling to avoid redundancy and update anomalies. Each fact row represents a single measurement event and contains only foreign keys to dimensions and numeric measures. Denormalization is reserved for dimension tables (for performance), not fact tables.