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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Database Administrator
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Device & Base Administrator
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Durable & Bicentric Automated
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Datebase Administrator
A
Correct answer
Explanation
DBA stands for Database Administrator, the person responsible for managing database systems. Option A correctly uses 'Database' and 'Administrator'. Option B incorrectly uses 'Device' and 'Base'. Option C is nonsensical. Option D has a typo 'Datebase' instead of 'Database'.
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Data Flow Data
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Data Fnd Data
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Data Fast Data
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Data Flow Diagram
D
Correct answer
Explanation
DFD stands for Data Flow Diagram, used to visualize the flow of data through a system. Option D correctly uses 'Data Flow' twice - data flowing through processes. Options A, B, and C incorrectly use variations like 'Fnd' (typo) and 'Fast' which are not part of the term.
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The two tables had their same Primary Index
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Teradata redistributed one or both tables by rehashing them by thePrimary index in spool
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Teradata placed the smaller table on all AMPs
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All the Above
D
Correct answer
Explanation
Teradata provides multiple mechanisms to enable joins to occur on the same AMP: identical primary indexes naturally distribute matching rows to the same AMP; dynamic redistribution can rehash tables during query processing; and duplicating small tables across all AMPs eliminates data movement. All three are valid join optimization strategies.
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String
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Decimal
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Date and Datetime
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Integer
C
Correct answer
Explanation
Date and Datetime types in Ab Initio are stored in binary form for efficiency in calculations and comparisons. While integers are also stored in binary, the question specifically asks about types known for binary storage of temporal data. Decimal stores as packed decimal, and string stores as character data. Date/Datetime is the best answer for binary-encoded temporal data.
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Loading data into table
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Unloading data from table
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Data is not loaded into all SPU’s
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All of the above
C
Correct answer
Explanation
Data skew is an uneven distribution of data across processing units (SPUs). When some SPUs receive significantly more data than others, they become bottlenecks while other SPUs sit idle. This defeats the purpose of parallel processing and severely degrades query performance. It's typically caused by poor distribution key choice in MPP databases.
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Already loaded records are visible to the user
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Already loaded records are logically deleted
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Already loaded records are Physically deleted
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None
B
Correct answer
Explanation
nzload is transactional - if it fails mid-operation, all partially loaded records are rolled back to maintain data integrity. This rollback is typically implemented by logically deleting the records (marking them as deleted). They remain on disk temporarily but are invisible to users and will be cleaned up by maintenance processes.
B
Correct answer
Explanation
Zonemaps in Netezza are automatically created and maintained by the system as metadata structures that track min/max values per data slice. Unlike indexes, users do not need to manually create or maintain zonemaps - they are built automatically during data loads.
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java.jdbc and javax.jdbc
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java.jdbc and java.jdbc.sql
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java.sql and javax.sql
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java.rdb and javax.rdb
C
Correct answer
Explanation
JDBC classes are distributed across java.sql (core JDBC API including Connection, Statement, ResultSet) and javax.sql (optional package including DataSource, ConnectionPool, RowSet). Options A and B incorrectly use 'jdbc' instead of 'sql', and option D invents non-existent 'rdb' packages.
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A transaction is a set of sql statements
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Auto commit to be set off before Transaction
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Auto commit to be set off after transaction
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Commit permanently records to database all changes waiting with current Connection
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Rollback is used in case of any error to undo transaction
C
Correct answer
Explanation
Transactions require auto-commit to be disabled BEFORE starting transactional operations. This allows multiple statements to be grouped together and either committed (all succeed) or rolled back (all fail) as a unit. Option C is false because auto-commit must be turned off before, not after, the transaction begins.
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DataBaseDirectory
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AdminHost
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ServerName
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PortNumber
C
Correct answer
Explanation
ServerName is the correct parameter in tm1s.cfg that uniquely identifies the TM1 application server. DataBaseDirectory specifies where data is stored, AdminHost is for administration, and PortNumber defines the communication port.
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To increase the number of dimensions and empty cells in a cube.
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To increase the sparsity of the dimensions and empty cells in a cube.
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To reduce the number of dimensions and empty cells in a cube.
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To reduce the density of the dimensions and string cells in a cube.
C
Correct answer
Explanation
Creating multiple hierarchies within a single dimension reduces the total number of dimensions needed in a cube, which consequently reduces the number of empty cells. Using separate dimensions for each hierarchy would dramatically increase sparsity.
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Consolidation
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Simple element
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Data Variable
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Attribute
B
Correct answer
Explanation
When loading data into a cube, each dimension must be mapped to a simple (leaf-level) element to identify the specific cell where data should be written. Consolidations and attributes are not used for data loading.
D
Correct answer
Explanation
A reporting cube and lookup cube can share data even with zero common dimensions. TM1's ability to reference cells across cubes doesn't require dimensional overlap - it uses cube-level references and dimension mappings.
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domainutility
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TIBCO Administrator
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MigrateFileStorage Utility
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MigrateDomainStorage Utility
C
Correct answer
Explanation
MigrateFileStorage Utility is the specific tool for migrating from file-based to database-based domain data repository storage. The domain utility is general-purpose, TIBCO Administrator doesn't perform migrations, and MigrateDomainStorage is not the correct utility name.
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java.jdbc and javax.jdbc
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java.jdbc and java.jdbc.sql
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java.sql and javax.sql
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java.rdb and javax.rdb
C
Correct answer
Explanation
JDBC core classes are in java.sql package. Extended JDBC API (for connection pooling, distributed transactions) is in javax.sql. There are no java.jdbc or java.rdb packages.