🛢DBMS: Candidate Key (Definitions)

"A unique identifier for a row within a database table. A candidate, or surrogate, key can be made up of one or more columns. In a normalized database, every table must have at least one candidate key, in which case it is considered the primary key for a table automatically. However, it is possible for a table to have more than one candidate key, in which case one of them must be designated as the primary key. Any candidate key that is not the primary key is called the alternate key." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"Any attribute or group of attributes that uniquely identifies each instance of an entity and that’s a possible choice for the primary key." (Sharon Allen & Evan Terry, "Beginning Relational Data Modeling" 2nd Ed., 2005)

"Also known as a potential key, or permissible key. A field or combination of fields, which can act as a primary key field for a table. A candidate key uniquely identifies each record in the table." (Gavin Powell, "Beginning Database Design", 2006)

"Any data item or group of data items which identify uniquely tuples in a relation." (S. Sumathi & S. Esakkirajan, "Fundamentals of Relational Database Management Systems", 2007)

"A minimal superkey. In other words, the fields in a candidate key uniquely define the records in a table and no subset of those fields also uniquely defines the records." (Rod Stephens, "Beginning Database Design Solutions", 2008)

"Any subset of the attributes (data items) in a superkey that is also a superkey and is not reducible to another superkey." (Toby J Teorey, ", Database Modeling and Design" 4th Ed., 2010)

"A column or set of columns that have a unique value for each row in a table." (Microsoft, "SQL Server 2012 Glossary", 2012)

"An attribute or set of attributes that can be used to uniquely identify an occurrence of the entity. Each entity may have one or more candidate keys. One of these candidate keys is selected as the table primary key." (Craig S Mullins, "Database Administration", 2012)

"A column or combination of columns that can be used as the primary key of a relation." (Jan L Harrington, "Relational Database Design and Implementation" 3rd Ed., 2009)

🛢DBMS: Role (Definitions)

"Provide individual accountability for users performing system administration and security-related tasks in SQL Server. The System Administrator, System Security Officer, and Operator roles can be granted to individual server login accounts." (Karen Paulsell et al, "Sybase SQL Server: Performance and Tuning Guide", 1996)

"An administrative unit within SQL Server that contains SQL Server logins, Windows NT logins, groups, or other roles." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"In Oracle, a named database object that can receive privileges and in turn be granted to accounts. Simplifies administration of privileges." (Bill Pribyl & Steven Feuerstein, "Learning Oracle PL/SQL", 2001)

"A security account that is a collection of other security accounts that can be treated as a single unit when managing permissions. A role can contain SQL Server logins, other roles, and Windows logins or groups." (Anthony Sequeira & Brian Alderman, "The SQL Server 2000 Book", 2003)

"A group of related privileges that is referenced by a single name. Privileges can be assigned to a role, and a role can be assigned to a database user or to another role. Roles ease the maintenance issues with managing privileges for a large number of users who can be grouped into a relatively small number of categories based on job function." (Bob Bryla, "Oracle Database Foundations", 2004)

"A SQL Server security account is a collection of other security accounts that can be treated as a single unit when managing permissions. A role can contain SQL Server logins, other roles, and Windows logins or groups." (Thomas Moore, "EXAM CRAM™ 2: Designing and Implementing Databases with SQL Server 2000 Enterprise Edition", 2005)

"A definition of security permissions for one or more user accounts or user groups defined in the operating system and applied to an OLAP database or cube." (Reed Jacobsen & Stacia Misner, "Microsoft SQL Server 2005 Analysis Services Step by Step", 2006)

"A set of privileges that permit actions on specified resources. Roles assigned to a user determine the user’s access to resources and operations." (MongoDb, "Glossary", 2008)

"Roles exist at both the server level and the database level. By adding logins to roles, they are automatically granted the permissions of that role. For example, by adding a user to the sysadmin role, the user can do anything on the instance of the server. By adding a user to the dbowner role, the user can do anything in the database." (Darril Gibson, "MCITP SQL Server 2005 Database Developer All-in-One Exam Guide", 2008)

"In Oracle, a named collection of database access privileges that authorize a user to connect to a database and use the database system resources." (Carlos Coronel et al, "Database Systems: Design, Implementation, and Management" 9th Ed., 2011)

"(1) Name used to refer to the logical set of related responsibilities assignable to a person or organization, and to parties with these assigned responsibilities. (2) A database security mechanism used to grant one or more preassigned privileges to a user." (Craig S Mullins, "Database Administration", 2012)

"A database entity that groups together one or more privileges and that can be assigned, for example, to users, PUBLIC, other roles, or trusted contexts." (Sybase, "Open Server Server-Library/C Reference Manual", 2019)

🛢DBMS: Covering Index (Definitions)

 [index covering]"A data access condition where the leaf-level pages of a nonclustered index contain the data needed to satisfy a query. The index must contain all columns in the select list as well as the columns in the query clauses, if any. The server can satisfy the query using only the leaf level of the index. When an index covers a query, the server does not access the data pages." (Karen Paulsell et al, "Sybase SQL Server: Performance and Tuning Guide", 1996)

"A nonclustered index that contains all of the columns required to satisfy a query, in both the selection list and the WHERE clause." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"An index that contains every column in the select list of a query." (Peter Gulutzan & Trudy Pelzer, "SQL Performance Tuning", 2002)

"An index where the values of the data are stored in the index, allowing data retrieval from the index itself, instead of the data object." (DAMA International, "The DAMA Dictionary of Data Management", 2011)

🛢DBMS: Foreign Key [FK] (Definitions)

"A key column in a table that logically depends on a primary key column in another table. Also, a column (or combination of columns) whose values are required to match a primary key in some other table." (Karen Paulsell et al, "Sybase SQL Server: Performance and Tuning Guide", 1996)

"The column or combination of columns whose values match the primary key (PK) or unique key in the same or another table. A foreign key does not have to be unique. A foreign key is often in a many-to-one relationship with a primary key. Foreign key values should be copies of the primary key values; no value in the foreign key except NULL should ever exist unless the same value exists in the primary key. A foreign key may be NULL; if any part of a composite foreign key is NULL, the entire foreign key must be NULL." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"A type of constraintthat enforces a logical relationshipbetween a row in one table and one or more rows in another table. Often, this is a master-detail relationship, where the primary key value of a row in one table appears in the "foreign key" column of one or more rows in another table." (Bill Pribyl & Steven Feuerstein, "Learning Oracle PL/SQL", 2001)

"A column in a relational database table whose values are drawn from the values of a primary key in another table. In a star-join schema, the components of a composite fact table key are foreign keys with respect to each of the dimension tables." (Ralph Kimball & Margy Ross, "The Data Warehouse Toolkit" 2nd Ed., 2002)

"A column or combination of columns whose values match the primary key (PK) or unique key in another table. The foreign key is also called the referencing key in some literature." (Anthony Sequeira & Brian Alderman, "The SQL Server 2000 Book", 2003)

"A column (or columns) in a table that draws its values from a primary or unique key column in another table. A foreign key assists in ensuring the data integrity of a table." (Bob Bryla, "Oracle Database Foundations", 2004)

"A column or multiple columns whose values match the Primary Key of another table. Foreign Keys help in the relational process between two entities by connecting the foreign attribute in the child entity to a Primary Key in a parent entity." (Thomas Moore, "EXAM CRAM™ 2: Designing and Implementing Databases with SQL Server 2000 Enterprise Edition", 2005)

"Column or combination of columns whose values are required to match a primary key in some other table." (Sharon Allen & Evan Terry, "Beginning Relational Data Modeling" 2nd Ed., 2005)

"A type of constraint where columns contain copies of primary key values, uniquely identified in parent entities, representing the child or sibling side of what is most commonly a one-to-many relationship." (Gavin Powell, "Beginning Database Design", 2006)

"Attribute or set of attributes that identifies the entity with which another entity is associated." (S. Sumathi & S. Esakkirajan, "Fundamentals of Relational Database Management Systems", 2007)

"Used to maintain relationships between entities. Implemented as a field in a child table that has a corresponding primary key that it references." (Marilyn Miller-White et al, "MCITP Administrator: Microsoft® SQL Server™ 2005 Optimization and Maintenance 70-444", 2007)

"An FK is used to create a relationship between two tables, and typically points to a PK (PRIMARY KEY) in another table. The relationship enforces integrity between the two tables, allowing only entries in the FK table that exist in the PK table, and preventing deletions from the PK table if a related entry exists in the FK table." (Darril Gibson, "MCITP SQL Server 2005 Database Developer All-in-One Exam Guide", 2008)

"Information that establishes a relationship between two tables. By preventing erroneous data modifications, this association helps preserve data integrity." (Robert D. Schneider & Darril Gibson, "Microsoft SQL Server 2008 All-In-One Desk Reference For Dummies", 2008)

"One or more columns that are related to values in corresponding columns in another table." (Rod Stephens, "Beginning Database Design Solutions", 2008)

"An attribute (or combination of attributes) in a relation that is the same as the primary key of another relation. A foreign key may be a non-key attribute in its own relation, or it may be part of a concatenated primary key." (Jan L Harrington, "Relational Database Design and Implementation" 3rd Ed., 2009)

"The column or combination of columns whose values match the primary key (PK) or unique key in the same or another table." (Jim Joseph, "Microsoft SQL Server 2008 Reporting Services Unleashed", 2009)

"An attribute in a relational table used for establishing the direct relationship with another table, known as the parent table. The values for the foreign key attribute are drawn from the primary key values of the parent table." (Paulraj Ponniah, "Data Warehousing Fundamentals for IT Professionals", 2010)

"Any attribute in a SQL table (key or nonkey) that is taken from the same domain of values as the primary key in another SQL table and can be used to join the two tables (without loss of data integrity) as part of a SQL query." (Toby J Teorey, ", Database Modeling and Design" 4th Ed., 2010)

"1.An attribute (or attributes) in a relational table which is from the same domain as the identifier of the same or another table; can be thought of as a logical pointer from the “referencing” entity table (with the foreign key) to the “referenced” entity table (with the identifier). It is used to represent a many-to-one relationship between the referencing and referenced tables. It is not necessary for a foreign key to have a value; that is determined by the independently defined dependency characteristic. 2.The preferred primary key of a parent data subject that is placed in a subordinate data subject to identify the relevant parent data occurrence in that parent data subject." (DAMA International, "The DAMA Dictionary of Data Management", 2011)

"Field whose purpose is to link two or more tables together." (Linda Volonino & Efraim Turban, "Information Technology for Management 8th Ed", 2011)

"A key in a database table that comes from another table (also know as the "referenced table") and whose values match the primary key (PK) or unique key in the referenced table." (Microsoft, "SQL Server 2012 Glossary", 2012)

"An attribute or set of attributes that identify relationships between entity occurrences." (Craig S Mullins, "Database Administration", 2012)

"One or more attributes that are included in one entity for the purpose of identifying another." (James Robertson et al, "Complete Systems Analysis: The Workbook, the Textbook, the Answers", 2013)

"An attribute used for distinguishing a record that participates in a relationship with another table" (Daniel Linstedt & W H Inmon, "Data Architecture: A Primer for the Data Scientist", 2014)

"A field that has a relationship to the primary key field in another table." (Faithe Wempen, "Computing Fundamentals: Introduction to Computers", 2015)

"An attribute of one table that is related to the primary key of another table." (Adam Gordon, "Official (ISC)2 Guide to the CISSP CBK" 4th Ed., 2015)

"In a relational database, a set of one or more fields in one table with values that uniquely define a record in another table. The table containing the foreign key is the child table, and the table that contains the uniquely identified record is the parent table." (Rod Stephens, "Beginning Software Engineering", 2015)

"A column or set of columns that refers to a parent key. In a relational database, a key in one table that references the primary key in another table. See also constraint, primary key, unique key." (Sybase, "Open Server Server-Library/C Reference Manual", 2019)

🛢DBMS: Key (Definitions)

"A field used to identify a record, often used as the index field for a table." (Karen Paulsell et al, "Sybase SQL Server: Performance and Tuning Guide", 1996)

"A column or group of columns that uniquely identifies a row (PRIMARY KEY), defines the relationship between two tables (FOREIGN KEY), or is used to build an index." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"A data element (attribute or column) or the combination of several used to identify a member of a set, instance of an entity, or record in a table." (Sharon Allen & Evan Terry, "Beginning Relational Data Modeling" 2nd Ed., 2005)

"A data item or combination of data items used to identify or locate a record instance (or other similar data groupings)." (William H Inmon, "Building the Data Warehouse", 2005)

"A specialized field determining uniqueness, or application of referential integrity through use of primary and foreign keys." (Gavin Powell, "Beginning Database Design", 2006)

"Key is a data item that helps to identify individual occurrences of an entity type." (S. Sumathi & S. Esakkirajan, "Fundamentals of Relational Database Management Systems", 2007)

"A column or group of columns that uniquely identifies a row (primary key), defines the relationship between two tables (foreign key), or is used to build an index." (Jim Joseph et al, "Microsoft SQL Server 2008 Reporting Services Unleashed", 2009)

"A generic term for a set of one or more attributes (data items) that, taken collectively, enables one to identify uniquely an entity or a record in a SQL table; a superkey." (Toby J Teorey, ", Database Modeling and Design" 4th Ed., 2010)

"A data item or combination of data items designated to uniquely identify a particular entity instance or table row." (DAMA International, "The DAMA Dictionary of Data Management", 2011)

"An entity identifier based on the concept of functional dependence; may be classified as follows: Superkey - an attribute (or combination of attributes) that uniquely identifies each entity in a table. Candidate key - a minimal superkey, that is, one that does not contain a subset of attributes that is itself a superkey. Primary key (PK) - a candidate key selected as a unique entity identifier." (Carlos Coronel et al, "Database Systems: Design, Implementation, and Management" 9th Ed., 2011)

"A column or group of columns that uniquely identifies a row (primary key), defines the relationship between two tables (foreign key), or is used to build an index." (Microsoft, "SQL Server 2012 Glossary", 2012)

"The attributes that identify entity occurrences and define relationships between entities." (Craig S Mullins, "Database Administration", 2012)

"An identifying attribute of data" (Daniel Linstedt & W H Inmon, "Data Architecture: A Primer for the Data Scientist", 2014)

"In a relational database, a set of one or more fields that uniquely identifies a record." (Rod Stephens, "Beginning Software Engineering", 2015)

"In key-value databases, a key is a reference to a value. In relational databases, a key is also a way to reference a row in a table. Primary keys refer to the way of uniquely identifying a row. Foreign keys refer to keys stored in one table that are used to reference rows in other tables." (Dan Sullivan, "NoSQL for Mere Mortals®", 2015)

"One or more fields of a database record that uniquely identifies it among all other records in the table." (Nell Dale & John Lewis, "Computer Science Illuminated" 6th Ed., 2015)

"Sequence of bits that are used as instructions that govern the acts of cryptographic functions within an algorithm." (Adam Gordon, "Official (ISC)2 Guide to the CISSP CBK" 4th Ed., 2015)

"A column or an ordered collection of columns that is identified in the description of an index, unique constraint, or referential constraint. An index key can also be an expression, an ordered collection of expressions, or an ordered collection of columns and expressions." (Sybase, "Open Server Server-Library/C Reference Manual", 2019)

"A subset of row data that uniquely identifies a row. Key data uniquely describes the current row in an open cursor." (Sybase, "Open Server Server-Library/C Reference Manual", 2019)

🛢DBMS: Primary Key [PK] (Definitions)

"The column or columns whose values uniquely identify a row in a table." (Karen Paulsell et al, "Sybase SQL Server: Performance and Tuning Guide", 1996)

"The column or combination of columns that uniquely identifies a table. It must always be non-null and will always have a unique index. A primary key is used for joins with foreign keys in other tables." (Patrick Dalton, "Microsoft SQL Server Black Book", 1997)

"A column (or columns) in a table that makes the row in the table distinguishable from every other row in the same table." (Bob Bryla, "Oracle Database Foundations", 2004)

"A column or set of columns that uniquely identify all the rows in a table." (Thomas Moore, "EXAM CRAM™ 2: Designing and Implementing Databases with SQL Server 2000 Enterprise Edition", 2005)

"A unique attribute used to identify a single record in a database." (William H Inmon, "Building the Data Warehouse", 2005)

"This is an index that ensures that each of the records in your table is unique in  some way." (Joseph L Jorden & Dandy Weyn, "MCTS Microsoft SQL Server 2005: Implementation and Maintenance Study Guide - Exam 70-431", 2006)

"A candidate key that is singled out as the table's 'main' method for uniquely identifying records. Most databases automatically build an index for a table's primary key and enforce uniqueness." (Rod Stephens, "Beginning Database Design Solutions", 2008)

"In relational theory, the set of columns whose values can be used to uniquely identify each row (tuple in Dr. Codd’s original terminology) in a table (relation to Dr. Codd)." (David C Hay, "Data Model Patterns: A Metadata Map", 2010)

"The unique key (normally) used for creating foreign keys pointing to the subject table from other tables." (David C Hay, "Data Model Patterns: A Metadata Map", 2010)

"A set of one or more data attributes whose values are used to uniquely identify an entity instance or relational database table row. The primary key will have a unique value for each record or row in the table and is the means of navigation across entities and tables. Primary key attributes and values of parent entities and tables appear as foreign key attributes and values in child entities and tables." (DAMA International, "The DAMA Dictionary of Data Management", 2011)

"The attribute, or set of attributes, that is used to uniquely identify an occurrence of the entity. Each entity must have one and only one primary key." (Craig S Mullins, "Database Administration", 2012)

🛢DBMS: Data Integrity (Definitions)

"The correctness and completeness of data within a database." (Karen Paulsell et al, "Sybase SQL Server: Performance and Tuning Guide", 1996)

"A general term that refers to the correctness of the data contained in a database." (Owen Williams, "MCSE TestPrep: SQL Server 6.5 Design and Implementation", 1998)

"The accuracy and reliability of data. Data integrity is important in both single-user and multiuser environments. In multiuser environments, where data is shared, both the potential for and the cost of data corruption are high. In large-scale relational database management system (RDBMS) environments, data integrity is a primary concern." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"Data integrity refers to a state in which all the data values stored in the database are correct." (Anthony Sequeira & Brian Alderman, "The SQL Server 2000 Book", 2003)

"The condition that exists when there’s no accidental or intentional destruction, alteration, or loss of data." (Sharon Allen & Evan Terry, "Beginning Relational Data Modeling" 2nd Ed., 2005)

"The bits of data that are put in storage (via I/O writes) are the same bits of data—order and completeness - that come out (via I/O reads)." (David G Hill, "Data Protection: Governance, Risk Management, and Compliance", 2009)

"In a relational database, refers to a condition in which the data in the database is in compliance with all entity and referential integrity constraints." (Carlos Coronel et al, "Database Systems: Design, Implementation, and Management 9th Ed", 2011)

"The accuracy of data and its conformity to its expected value, especially after being transmitted or processed." (Microsoft, "SQL Server 2012 Glossary", 2012)

"Refers to the accuracy and quality of the data." (Steve Conger, "Hands-on database : an introduction to database design and development", 2012)

"Data integrity is the state of data being free from corruption." (Vince Buffalo, "Bioinformatics Data Skills", 2015)

"The property that data has not been altered in an authorized manner." (O Sami Saydjari, "Engineering Trustworthy Systems: Get Cybersecurity Design Right the First Time", 2018)

"The degree to which the data is internal or referential/consistent. If the key to refer to a different table is invalid, the join between the two tables cannot be made." (Piethein Strengholt, "Data Management at Scale", 2020)

"(1) In the context of data and network security: The assurance that information can only be accessed or modified by those authorized to do so. (2) In the context of data quality: The assurance the data are clean, traceable, and fit for purpose." (CODATA)

"The degree to which a collection of data is complete, consistent, and accurate. See also: data security; database integrity; integrity." (IEEE 610.5-1990)

🛢DBMS: Atomic(-level) Data (Definitions)

"Data elements that represent the lowest level of granularity. Depending on the context, this term may refer all the way back to the transactions from the operational systems, or it may refer to the base granularity held in a data warehouse." (Microsoft Corporation, "Microsoft SQL Server 7.0 Data Warehouse Training Kit", 2000)

"The most detailed granular data captured by a business process. Atomic data must be made available in the data presentation area to respond to unpredictable ad hoc queries." (Ralph Kimball & Margy Ross, "The Data Warehouse Toolkit 2nd Ed ", 2002)

"Data elements that represent the lowest level of detail. For example, in a daily sales report, the individual items sold would be atomic data, and roll-ups such as invoice and summary totals from invoices are aggregate data." (Sharon Allen & Evan Terry, "Beginning Relational Data Modeling 2nd Ed.", 2005)

"Data with the lowest level of granularity. Atomic-level data sits in a data warehouse and is time-variant (that is, accurate as of some moment in time now passed)." (William H Inmon, "Building the Data Warehouse", 2005)

"1.Data at the lowest chosen level of detail (granularity). The level of detail chosen depends on the information requirements of the enterprise. For example, address could be one atomic item, or address could be split into further composite items such as house identifier and city. Opposite of aggregate data. 2.Non-aggregated observations, or measurements of characteristics of individual units, which cannot be further decomposed and retain any useful meaning." (DAMA International, "The DAMA Dictionary of Data Management", 2011)

"Data at the lowest available level of detail or granularity." (Craig S Mullins, "Database Administration", 2012)

🛢DBMS: Column (Definitions)

"The logical equivalent of a field. A column contains an individual data item within a row or record." (Karen Paulsell et al, "Sybase SQL Server: Performance and Tuning Guide", 1996)

"In a SQL database table, the area, sometimes called a field, in each row that stores the data about an attribute of the object modeled by the table (for example, the ContactName column in the Customers table of the Northwind database). Individual columns are characterized by their maximum length and the type of data that can be placed in them. A column contains an individual data item within a row." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"A named portion of a table that can hold some number of data values of a particular datatype. Columns usually have some maximum width or number of bytes. The names and datatypes of a table's columns typically do not vary over time." (Bill Pribyl & Steven Feuerstein, "Learning Oracle PL/SQL", 2001)

"The area in each row that stores the data value for some attribute of the object modeled by the table." (Anthony Sequeira & Brian Alderman, "The SQL Server 2000 Book", 2003)

"The component of a database table that contains all of the data of the same name and type across all rows." (Bob Bryla, "Oracle Database Foundations", 2004)

"A piece of data that may be recorded for each row in a table. The corresponding formal database term is attribute." (Rod Stephens, "Beginning Database Design Solutions", 2008)

"Stored within tables, a column contains a particular piece of information." (Robert D Schneider & Darril Gibson, "Microsoft SQL Server 2008 All-in-One Desk Reference For Dummies", 2008)

"In a table, the area in each row that stores the data value for some attribute of the object presented in the table. For example, in an Employee table, a FirstName column would contain the first name of an employee." (Jim Joseph, "Microsoft SQL Server 2008 Reporting Services Unleashed", 2009)

"A data attribute as implemented in a relational database as a vertical component of a table, similar to a field in a flat file record." (Craig S Mullins, "Database Administration", 2012)

"The area in each row of a database table that stores the data value for some attribute of the object modeled by the table." (Microsoft, "SQL Server 2012 Glossary", 2012)

"A column is the data structure for storing a single value in a column family database." (Dan Sullivan, "NoSQL for Mere Mortals", 2015)

"The vertical component of a database table. A column has a name and a particular data type (for example, character, decimal, or integer)." (Sybase, "Open Server Server-Library/C Reference Manual", 2019)

🛢DBMS: Flat File (Definitions)

"A simple data structure, often implemented on a mainframe, that relies on nonrelational files, such as IBM VSAM files." (Ralph Kimball & Margy Ross, "The Data Warehouse Toolkit 2nd Ed ", 2002)

"A collection of records containing no data aggregates, nested repeated data items, or groups of data items." (William H Inmon, "Building the Data Warehouse", 2005)

"A collection of records that are related to one another that haven’t been organized to meet relational normal forms. Originally a file was stored only outside a database. Now you can refer to a table structured this way as a flat file." (Sharon Allen & Evan Terry, "Beginning Relational Data Modeling" 2nd Ed., 2005)

"A data structure that contains records with no inherent relationships." (Evan Levy & Jill Dyché, "Customer Data Integration", 2006)

"A term generally applying to an unstructured file, such as a text file." (Gavin Powell, "Beginning Database Design", 2006)

"A file in which the fields of records are simple atomic values." (S. Sumathi & S. Esakkirajan, "Fundamentals of Relational Database Management Systems", 2007)

"A plain old text file used to store data. A flat file isn't very fancy and provides few tools for querying, sorting, grouping, and performing other database operations but flat files are very easy to use." (Rod Stephens, "Beginning Database Design Solutions", 2008)

"A file in which all the attribute fields are atomic, that is, single valued." (DAMA International, "The DAMA Dictionary of Data Management", 2011)

"A file consisting of records of a single record type in which there is no embedded structure information that governs relationships between records." (Microsoft, "SQL Server 2012 Glossary", 2012)

"Plain text file wherein each line of the file holds one record, typically with fields separated by delimiters, such as commas or tabs." (Craig S Mullins, "Database Administration", 2012)

"A collection of records where the structure of each record is identical" (Daniel Linstedt & W H Inmon, "Data Architecture: A Primer for the Data Scientist", 2014)

🛢SQL Server: Parameterization (Definitions)

"Parameterization is the act of using named or positional markers in place of constant values in a T-SQL query or statement. The actual values are passed to SQL Server independently of the actual query." (Michael Coles, "Pro T-SQL 2008 Programmer's Guide", 2008)

"The act of using parameters or parameter markers rather than constant values." (Jim Joseph, "Microsoft SQL Server 2008 Reporting Services Unleashed", 2009)

"Parameterization is the act of using named or positional markers in place of constant values in a T-SQL query or statement. The actual values are passed to SQL Server independently of the actual query." (Jay Natarajan et al, "Pro T-SQL 2012 Programmer's Guide" 3rd Ed., 2012)

"The act of using named or positional markers in place of constant values in a T-SQL query or statement. The actual values are passed to SQL Server independently of the actual query." (Miguel Cebollero et al, "Pro T-SQL Programmer’s Guide" 4th Ed., 2015)

🛢DBMS: Data Model (Definitions)

"A method of organizing data into two-dimensional tables made up of rows and columns. The model is based on the mathematical theory of relations, a part of set theory." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"A representation, usually graphical, of objects and their relationships, generally undertaken as part of designing an Oracle database application." (Bill Pribyl & Steven Feuerstein, "Learning Oracle PL/SQL", 2001)

"A formal way of describing the relationship between entities in a database to a database management system." (Jan L Harrington, "Relational Database Dessign: Clearly Explained" 2nd Ed., 2002)

"A data model is an abstraction or representation of the data in a given environment. It is a collection and subsequent verification and communication method for fully documenting the data requirements used in the creation of accurate, effective, and efficient physical databases. The data model consists of entities, attributes, and relationships." (Claudia Imhoff et al, "Mastering Data Warehouse Design", 2003)

"A data model is a schematic showing the data in the warehouse, how the data relate to other data, and how the data should be structured. It is used to ensure that the data warehouse can substantiate all business requirements." (Margaret Y Chu, "Blissful Data", 2004)

"An integrated collection of concepts for describing data, relationships between data, and constraints on the data used by an organization." (Thomas M Connolly & Carolyn E Begg, "Database Solutions: A step-by-step guide to building databases", 2004)

"The specification of data structures and business rules needed to support a defined set of functions (sometimes called an Information Model); usually depicted in a diagram consisting of entities and relationships." (Margaret Y Chu, "Blissful Data ", 2004)

"(1) A data model is an abstract, self-contained, logical definition of the data structures, data operators, and so forth, that together make up the abstract machine with which users interact. (2) A data model is a model of the persistent data of some particular enterprise." (Christopher J Date, "Database in Depth", 2005)

"A data model is the specification of data structures and business rules to represent business requirements. This is an abstraction that describes one or more aspects of a problem or a potential solution addressing a problem." (Sharon Allen & Evan Terry, "Beginning Relational Data Modeling" 2nd Ed., 2005)

"A model that provides a two-dimensional structure to data." (Gavin Powell, "Beginning Database Design", 2006)

[object database model:] "A model that provides a three-dimensional structure to data where any item in a database can be retrieved from any point very rapidly." (Gavin Powell, "Beginning Database Design", 2006)

"(1) The logical data structures, including operations and constraints provided by a DBMS for effective database processing; (2) the system used for the representation of data (for example, the ERD or relational model). " (William H Inmon & Anthony Nesavich, "Tapping into Unstructured Data", 2007)

"A formal description of data managed by a business process. In most cases, these data are stored via a Database Management System (DBMS), and are also referenced by an Information System (IS) and, possibly, by a Decision Support Systems (DSS)" (C Combi & G Pozzi, "Workflow Management Systems for Healthcare Processes", 2008)

[Entity Data Model] "An EDM is an abstract logical representation of a physical database, used to implement database connectivity in the middle or client tiers." (Michael Coles, "Pro T-SQL 2008 Programmer's Guide", 2008)

[navigational data model:] "A data model where relationships between entities are represented by physical data structures (for example, pointers or indexes) that provide the only paths for data access." (Jan L Harrington, "Relational Database Design and Implementation" 3rd Ed., 2009)

"A formal description language to describe and to manipulate the investigated data instances. It contains three components: a static structural part, an integrity part and a manipulation part." (László Kovács & Tanja Sieber, "Multi-Layered Semantic Data Models" [in "Encyclopedia of Artificial Intelligence"], 2009)

"A paradigm for describing the structure of a database in which entities are represented as tables, and relationships between the entities are represented by matching data." (Jan L Harrington, "Relational Database Design and Implementation" 3rd Ed., 2009)

"An abstraction of how individual data elements relate to each other. It visually depicts how the data is to be organized and stored in a database. A data model provides the mechanism to document and understand how data is organized. (Laura Reeves, "A Manager's Guide to Data Warehousing", 2009)

"The formal way of expressing relationships in a database." (Jan L Harrington, "Relational Database Design and Implementation" 3rd Ed., 2009)

"A representation of the structure of data. As used in this book, the term refers to a conceptual data model, which describes data in terms of their inherent semantics, without regard to how they might be organized in a physical database. Some use the term to describe a logical data model that organizes data in terms of a specific data management technology, such as relational tables and columns, object-oriented classes, or ISAM hierarchies." (David C Hay, "Data Model Patterns: A Metadata Map", 2010)

"A model that includes formal data names, comprehensive data definitions, proper data structures, and precise data integrity rules. A complete data model must include all four of these components." (DAMA International, "The DAMA Dictionary of Data Management", 2011)

"A representation, usually graphic, of a complex 'real-world' data structure. Data models are used in the database design phase of the database life cycle." (Carlos Coronel et al, "Database Systems: Design, Implementation, and Management 9th Ed", 2011)

"A data model is a visual representation of data content and the relationships, created for purposes of understanding how data is or might be organized, and for ensuring the comprehensibility and usability of that way of organizing data." (Laura Sebastian-Coleman, "Measuring Data Quality for Ongoing Improvement ", 2012)

"A representation, usually graphic, of a complex 'real-world' data structure. Data models are used in the database design phase of the database life cycle." (Carlos Coronel & Steven Morris, "Database Systems: Design, Implementation, & Management" 11th Ed., 2014)

[Entity Data Model (EDM):] "An abstract logical representation of a physical database, used to implement database connectivity in the middle or client tiers." (Miguel Cebollero et al, "Pro T-SQL Programmer’s Guide 4th Ed", 2015)

"Represents data objects and their relationships with each other. Data models form the basis for data integration at the conceptual level as well as the improvement of data quality, such as with regard to the reduction of data redundancy.  Data models are one component of the data architecture." (Boris Otto & Hubert Österle, "Corporate Data Quality", 2015)

"A visual means of depicting data and its relationship to other data." (Gregory Lampshire, "The Data and Analytics Playbook", 2016)

"A description of the objects represented by a computer system together with their properties and relationships." (Besma Khalfi et al, "Enhanced F-Perceptory Approach for Dealing with Geographic Data Imprecision from the Conceptual Modeling to the Fuzzy Geographical Database Building", 2017)

"1. A representation, using text and/or graphics, of the definition, characterization, and relationships of data in a given environment. 2. No longer used, the DBMS architecture (hierarchical, network, relational, etc.)." (George Tillmann, "Usage-Driven Database Design: From Logical Data Modeling through Physical Schmea Definition", 2017)

"In a data-centric benchmark, a database schema and a protocol for instantiating this schema, i.e. , generating synthetic data or reusing real-life data." (Jérôme Darmont, "Data-Centric Benchmarking", Encyclopedia of Information Science and Technology, Fourth Edition, 2018)

"An abstract model that describes how data is presented and used." (Piethein Strengholt, "Data Management at Scale", 2020)

"A description of data that consists of all entities represented in a data structure or database and the relationships that exist among them." (IEEE 610.5-1990)

🛢DBMS: Constraints (Definitions)

"A restriction placed upon the value that can be entered into a column or a row. Values can be equal to, greater than, or less than. A constraint limits the input." (Patrick Dalton, "Microsoft SQL Server Black Book", 1997)

"A property assigned to a table column that prevents certain types of non-valid data values from being placed in the column." (Anthony Sequeira & Brian Alderman, "The SQL Server 2000 Book", 2003)

"A condition defined against a column or columns on a table in the database to enforce business rules or relationships between tables in the database." (Bob Bryla, "Oracle Database Foundations", 2004)

"A database object that can be applied to tables to enforce different types of data integrity." (Sara Morganand & Tobias Thernstrom , "MCITP Self-Paced Training Kit : Designing and Optimizing Data Access by Using Microsoft SQL Server 2005 - Exam 70-442", 2007)

"(1) A restriction on a business action and the resulting data. (2) The database mechanism for enforcing such." (Craig S Mullins, "Database Administration: The Complete Guide to DBA Practices and Procedures 2nd Ed", 2012)

"A rule that limits the values that can be inserted, deleted, or updated in a table." (Sybase)

🛢DBMS: Data Source (Definitions)

"The source of data for an object such as a cube or a dimension. Also, the specification of the information necessary to access source data. Sometimes refers to a DataSource object." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"A repository for storing data. An ODBC/JDBC term." (Peter Gulutzan & Trudy Pelzer, "SQL Performance Tuning", 2002)

"A file that contains the connection string that Analysis Services uses to connect to the database that hosts the data as well as any necessary authentication credentials." (Reed Jacobsen & Stacia Misner, "Microsoft SQL Server 2005 Analysis Services Step by Step", 2006)

"A system or application that generates data for use by another system or by an end user. The data source may also be the system of origin for the data." (Evan Levy & Jill Dyché, "Customer Data Integration", 2006)

"An information store that can be connected to by various SQL Server technologies such as SQL Server Reporting Services for data retrieval." (Marilyn Miller-White et al, "MCITP Administrator: Microsoft® SQL Server™ 2005 Optimization and Maintenance 70-444", 2007)

"An entity or group of entities from which data can be collected. The entities may be people, objects, or processes." (Jens Mende, "Data Flow Diagram Use to Plan Empirical Research Projects", 2009)

"An object containing information about the location of data. The data source leverages a connection string." (Jim Joseph et al, "Microsoft® SQL Server™ 2008 Reporting Services Unleashed", 2009)

"A repository of data to which a federated server can connect and then retrieve data by using wrappers. A data source can contain relational databases, XML files, Excel spreadsheets, table-structured files, or other objects. In a federated system, data sources seem to be a single collective database." (Sybase, "Open Server Server-Library/C Reference Manual", 2019)

🛢DBMS: Scalar Aggregate (Definitions)

"An aggregate function that produces a single value from a select statement that does not include a group by clause. This is true whether the aggregate function is operating on all the rows in a table or on a subset of rows defined by a where clause." (Karen Paulsell et al, "Sybase SQL Server: Performance and Tuning Guide", 1996)

[vector aggregate:] "A value that results from using an aggregate function with a group by clause." (Karen Paulsell et al, "Sybase SQL Server: Performance and Tuning Guide", 1996)

"When aggregate functions are applied to the whole or partial table without the GROUP BY clause and return only one row." (Owen Williams, "MCSE TestPrep: SQL Server 6.5 Design and Implementation", 1998)

[vector aggregates:] "When aggregate functions are used with the GROUP BY clause, they return values for each group. These are called vector aggregates." (Owen Williams, "MCSE TestPrep: SQL Server 6.5 Design and Implementation", 1998)

"A function applied to all of the rows in a table (producing a single value per function). An aggregate function in the select list with no GROUP BY clause applies to the whole table and is an example of a scalar." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

[vector aggregate:] "Functions applied to all rows that have the same value in a specified column or expression by using the GROUP BY clause and, optionally, the HAVING clause (producing a value for each group per function)." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"An aggregate value that is calculated on the data source. Depending on the data source, server aggregates can be treated as detail data or as aggregates based on the dataset option InterpretSubtotalsAsDetails." (Microsoft Technet)

[aggregate of aggregates:] "A summary value calculated from aggregates, such as the maximum of a set of sums." (Microsoft Technet)

 "An aggregate function, such as MIN(), MAX(), or AVG(), that is specified in a SELECT statement column list that contains only aggregate functions." (Microsoft Technet)