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42 Cards in this Set
- Front
- Back
The smallest unit of application data recognized by system software.
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Field
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A detailed coding scheme recognized by system software, such as a DBMS, for representing organizational data.
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Data Type
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The value a field will assume unless a user enters an explicit value for an instance of that field.
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Default Value
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This limits the set of permissible values may assume.
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Range Control
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An empty value.
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Null Value Control
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A form of range control in which the value of a field must exist as the value in some field in another row of the same or a different table.
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Referential Integrity
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The process of transforming normalized relations into non-normalized physical record specifications.
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Denormalization
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Distribution of the rows of a logical relation into several separate tables.
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Horizontal Partitioning
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Distribution of the columns of a logical relation into several separate physical tables.
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Vertical Partitioning
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A named portion of a secondary memory allocated for the purpose of storing physical records.
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Physical File
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A named logical storage unit in which data from one or more database tables, views or other database objects may be stored.
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Tablespace
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A contiguous section of disk storage space.
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Extent
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A technique for physically arranging the records of a file on secondary storage files.
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File Organization
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The storage of records in a file in sequence according to a primary key value.
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Sequential File Organization
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The storage of records either sequentially or non-sequentially with an index that allows software to locate individual files.
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Indexed File Organization
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A table or other data structure used to determine in a file the location of records that satisfy some condition.
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Index
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One field or a combination of fields for which more than one record may have the same combination of values.
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Secondary (non unique) Key
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An index on columns from two or more tables that come from the same domains of values.
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Join Index
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A storage system in which the address for each record is determined using a hashing algorithm
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Hashed File Organization
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A routine that converts a primary key value into a record number of relative file address.
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Hashing Algorithm
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A file organization that uses hashing to map a key into a location in an index, where there is a pointer to the actual data record matching the hash key.
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Hash Index Table
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A field of data indicating a target address that can be used to locate a related field of record data.
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Pointer
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A named two-dimensional table of data.
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Relation
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An attribute or a combination of attributes that uniquely identifies each row as a relation.
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Primary Key
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A primary key that consists of more than one attribute
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Composite Key
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An attribute in a relation that serves as the primary key of another relation in the same database.
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Foreign Key
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A state of a relation that requires that certain rules regarding relationships between attributes are satisfied.
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Normal Form
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A constraint between two attributes in which the value of one attribute is determined by the value of another attribute.
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Functional Dependency
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The attribute on the left side of the arrow in a functional dependency.
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Determinant
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An attribute or combination of attributes, that uniquely identifies a row in a relation.
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Candidate Key
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A relation that has a primary key and in which there are no repeating groups.
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First Normal Form
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A relation in first normal form in which every nonkey attribute is fully functionally dependent on the primary key.
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Second Normal Form
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A functional dependency in which one or more nonkey attributes are functionally dependent on part but not all of the primary key,
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Partial Functional Dependency
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A relation that is in second normal form and has no more transitive dependencies.
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Third Normal Form
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A functional dependency between the primary key and one or more nonkey attributes that are dependent on the primary key via another nonkey attribute,
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Transitive Dependency
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Two or more attributes that have different name but the same meaning.
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Synonyms
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An alternative name used for an attribute
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Alias
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An attribute may have more than one meaning.
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Homonym
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A rule that states that either each foreign key value must match a primary key value in another relation or the foreign key value must be null.
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Referential Integrity Constraint
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A relation that contains minimal redundancy and allows users to insert, modify, and delete the rows in a table without errors or inconsistencies.
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Well-Structured Relation
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An error or inconsistency that may result when a user attempts to update a table that contains redundant data. The three types of anomalies are insertion, deletion, and modification anomalies.
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Anomaly
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A primary key whose value is unique across all relations.
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Enterprise Key
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