🛢DBMS: Conceptual Data Model (Definitions)

"Represents the overall logical structure of a database, which is independent of any software or data storage structure. A Conceptual model often contains data objects not yet implemented in the physical databases. It gives a formal representation of the data needed to run an enterprise or a business activity." (Sharon Allen & Evan Terry, "Beginning Relational Data Modeling" 2nd Ed., 2005)

"An organization of data that describes the relationships among the primitive data elements. For example, in the ER model, it is a diagram of the entities, their relationships, and their attributes." (Sam Lightstone et al, "Physical Database Design: The Database Professional’s Guide to Exploiting Indexes, Views, Storage, and More", 2007)

"An abstract model or representation of data for a particular domain, business enterprise, field of study, etc., independent of any specific software or information system. Usually expressed in terms of entities and relationships." (J P Getty Trust, "Introduction to Metadata" 2nd Ed., 2008)

"An organization of data that describes the relationships among the primitive data elements. For example, in the ER model, it is a diagram of the entities, their relationships, and their attributes." (Toby J Teorey, ", Database Modeling and Design" 4th Ed, 2010)

"In the ANSI four-schema architecture, this is a description of a portion of an enterprise in terms of the fundamental things of significant interest to it. They are fundamental in that most things seen by business owners are examples of these. The model is constructed in a rigorous manner, being fully normalized, eschewing many-to-many relationships and is expressed in terms of binary relationships only." (David C Hay, "Data Model Patterns: A Metadata Map", 2010)

"A data model that is presented at a high level of abstraction, hiding the underlying details, and making it easier for people to comprehend. A conceptual model should reflect the phenomena in the users' world being modeled as directly as possible, as close to the way the users think. For example, many-to-many relationships are common in conceptual models." (DAMA International, "The DAMA Dictionary of Data Management", 2011)

"A high-level data model identifying major entities and relationships, not fully attributed and therefore not necessarily normalized." (Craig S Mullins, "Database Administration: The Complete Guide to DBA Practices and Procedures" 2nd Ed., 2012)

"A high-level data modeling that specifies an abstract map of concepts and their relationships. SQL’s inherent hierarchical data modeling does this easily and naturally." (Michael M David & Lee Fesperman, "Advanced SQL Dynamic Data Modeling and Hierarchical Processing", 2013)

"A detailed model that captures the overall structure of organizational data that is independent of any database management system or other implementation considerations." (Jeffrey A. Hoffer et al, "Modern Systems Analysis and Design" 7th Ed., 2014)

"The output of the conceptual design process. The conceptual model provides a global view of an entire database. Describes the main data objects, avoiding details." (Carlos Coronel & Steven Morris, "Database Systems: Design, Implementation, & Management"  Ed. 11, 2014)

"A model of a database expressed at platform independent level; describes entities from a considered domain, properties of these entities, and the relationships between entities." (Iwona Dubielewicz et al, "Quality-Driven Database System Development within MDA Approach", 2015)

"The most abstract form of data model. It includes the important entities and the relationships among them and contains only major attributes." (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)

🛢DBMS: Dataset (Definitions)

"In general, a collection of related information made up of separate elements that can be treated as a unit. In OLE DB for OLAP, the set of multidimensional data that is the result of executing a multidimensional expression (MDX) statement. For more information about datasets, see your OLE DB documentation." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"A set of data that is the result of executing Transact-SQL SELECT, Data Mining Expressions (DMX), or Multidimensional Expressions (MDX) statements." (Jim Joseph, "Microsoft SQL Server 2008 Reporting Services Unleashed", 2009)

"Any organized collection of data." (DAMA International, "The DAMA Dictionary of Data Management", 2011)

"In ADO.NET, refers to a disconnected memory-resident representation of the database. That is, the DataSet contains tables, columns, rows, relationships, and constraints." (Carlos Coronel et al, "Database Systems: Design, Implementation, and Management" 9th Ed., 2011)

"A collection of related information made up of separate elements that can be treated as a unit in data handling." (Microsoft, "SQL Server 2012 Glossary", 2012)

"Dataset is a general term for referring to a collection of data; most often I have used it to refer to a collection of data that will be measured." (Laura Sebastian-Coleman, "Measuring Data Quality for Ongoing Improvement ", 2012)

"A collection of related measurements. In the data-mining context, this usually refers to an organized electronic file or database containing records of routine business activity or other information relevant to a particular data-mining project." (Meta S Brown, "Data Mining For Dummies", 2014)

"Collection of data corresponding to the contents of a single database." (Hamid R Arabnia et al, "Application of Big Data for National Security", 2015)

"A collection of variables or information that is composed of separate elements but can be managed as a single entity for analysis." (Jonathan Ferrar et al, "The Power of People", 2017)

"Any organised collection of data. ‘Dataset’ is a flexible term and may refer to an entire database, a spreadsheet or other data file, or a related collection of data resources." (Open Data Handbook)

"Refers to a grouping of individual, but related, data points that a computer can process as a single unit. Datasets are referred to as 'big data' when they’re too large to be handled by traditional data processing applications." (Accenture)

🛢DBMS: Entity Integrity (Definitions)

"Within a table, each row describes an entity that is a member of the set kept in the table. Entity integrity ensures that each row in the table is uniquely identifiable." (Owen Williams, "MCSE TestPrep: SQL Server 6.5 Design and Implementation", 1998)

"Integrity that defines a row as a unique entity for a particular table and ensures that the column cannot contain duplicate values. It usually enforces the primary key of a table (through indexes, UNIQUE constraints, or PRIMARY KEY constraints)." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"Entity integrity refers to a state in which all the rows in a database have a non-null primary key value, all tables have primary keys, and no table has any duplicate primary key values. Entity integrity ensures there are no duplicate entries for anything represented in the database." (Anthony Sequeira & Brian Alderman, "The SQL Server 2000 Book", 2003)

"A relational database integrity mechanism that ensures that duplicate rows do not exist in a table. Requiring that all rows in a table have a unique identifier." (Victor Isakov et al, "MCITP Administrator: Microsoft SQL Server 2005 Optimization and Maintenance (70-444) Study Guide", 2007)

"Integrity that defines a row as a unique entity for a particular table and ensures that the column cannot contain duplicate values." (S. Sumathi & S. Esakkirajan, "Fundamentals of Relational Database Management Systems", 2007)

"Requires that all tables have a primary key. The values in the primary key fields must be non-null and no two records can have the same primary key values." (Rod Stephens, "Beginning Database Design Solutions", 2008)

"A constraint on a relation that states that no part of the primary key can be null." (Jan L Harrington, "Relational Database Design and Implementation' 3rd Ed., 2009)

"The property of a relational table that guarantees that each entity has a unique value in a primary key and that there are no null values in the primary key." (Carlos Coronel et al, "Database Systems: Design, Implementation, and Management" 9th Ed., 2011)

"A state in which every row of every table can be uniquely identified." (Microsoft, "SQL Server 2012 Glossary", 2012)

"The most basic level of data integrity provided by relational databases stating that each occurrence of an entity must be uniquely identifiable." (Craig S Mullins, "Database Administration", 2012)

🛢DBMS: Data definition (Definitions)

"The process of setting up databases and creating database objects such as tables, indexes, rules, defaults, procedures, triggers, and views." (Karen Paulsell et al, "Sybase SQL Server: Performance and Tuning Guide", 1996)

"A data definition specifies the attributes, properties, and objects in a database." (Anthony Sequeira & Brian Alderman, "The SQL Server 2000 Book", 2003)

"Specification of data entities, including their attributes and relationships, in a coherent database structure to create a schema." (Sharon Allen & Evan Terry, "Beginning Relational Data Modeling" 2nd Ed., 2005)

"1.Statements that specify the business meaning associated with a conceptual, logical, or physical data entity or attribute. 2.The process of creating business meta-data, including names, meanings, integrity rules, and domain values. 3.In computer programming, the statements in a computer program that specify the physical attributes of the data to be processed, such as location and quantity of data." (DAMA International, "The DAMA Dictionary of Data Management", 2011)

"The attributes, properties, and objects in a database." (Microsoft, "SQL Server 2012 Glossary", 2012)

"An executable statement where a variable is assigned a value." (Software Quality Assurance)

🛢DBMS: Correlated Subquery (Definitions)

 "A subquery that cannot be evaluated independently, but depends on the outer query for its results. Also called a repeating subquery, since the subquery is executed once for each row that might be selected by the outer query. See also nested query." (Karen Paulsell et al, "Sybase SQL Server: Performance and Tuning Guide", 1996)

"A repeating subquery. Many queries can be evaluated by executing the subquery once and substituting the resulting value or values into the WHERE clause of the outer query. In queries that include a correlated subquery, the subquery depends on the outer query for its values. This means that the subquery is executed repeatedly, one time for each row that is selected by the outer query." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"A subquery that references a column in an outer statement. The inner query is executed for each candidate row in the outer statement." (Anthony Sequeira & Brian Alderman, "The SQL Server 2000 Book", 2003)

"A subquery that contains a reference to a column in the main, or parent, query." (Bob Bryla, "Oracle Database Foundations", 2004)

"A subquery that a DBMS cannot process completely before turning to the outer query. The DBMS must execute the subquery repeatedly for every row in the outer query." (Jan L Harrington, "SQL Clearly Explained 3rd Ed. ", 2010)

"A subquery that contains a correlated reference." (Sybase, "Open Server Server-Library/C Reference Manual", 2019)

🛢DBMS: Ad-hoc Query (Definitions)

"A query created for immediate execution. You can create an ad hoc query from scratch or by modifying an existing query that is saved in a text file." (Patrick Dalton, "Microsoft SQL Server Black Book", 1997)

"A query consisting of dynamically constructed SQL. Desktop query tools are often used to construct ad hoc queries. The opposite of a static query." (Microsoft Corporation, "Microsoft SQL Server 7.0 Data Warehouse Training Kit", 2000)

"An original or unplanned query that is used for in-depth analysis or to solve a specific problem." (Margaret Y Chu, "Blissful Data ", 2004)

"Any query that can’t be determined (isn’t stored and reused) prior to the moment the query is issued. It’s usually dynamically constructed Structured Query Language (SQL), often by desktop-resident query tools." (Sharon Allen & Evan Terry, "Beginning Relational Data Modeling" 2nd Ed., 2005)

"A query sent to a database by an end-user or power user, just trying to get some information quickly. Ad-hoc queries are subjected to a database where the content, structure, and performance of said query, are not necessarily catered for by the database model. The result could be a performance problem, and in extreme cases, even an apparent database halt." (Gavin Powell, "Beginning Database Design", 2006)

"A query issued infrequently, or on an as-needed basis." (Robert D Schneider & Darril Gibson, "Microsoft SQL Server 2008 All-in-One Desk Reference For Dummies", 2008)

"A query that is executed infrequently. Ad hoc queries can sometimes be troublesome because untrained users can create queries that are inefficient, causing the server to suffer significant performance degradation." (Darril Gibson, "MCITP SQL Server 2005 Database Developer All-in-One Exam Guide", 2008)

"A query issued infrequently, or on an as-needed basis. Typically ad hoc queries are issued against remote data sources from a SQL Server, but can also be issued against SQL Server from a wide variety of sources. If you have a need to issue queries against a remote data source more often, linked servers are created to simplify the syntax of the ad hoc query." (Robert D. Schneider and Darril Gibson, "Microsoft SQL Server 2008 All-In-One Desk Reference For Dummies", 2008)

"A query constructed and executed to answer an immediate and unanticipated question or need, in contrast to a planned query. For example, a dynamic SQL SELECT statement against a relational database, constructed by a knowledge worker using an English-like or point-and-click interface of a desktop-resident Business Intelligence tool. The data returned may drive further analysis and reporting." (DAMA International, "The DAMA Dictionary of Data Management", 2011)

"A query constructed and executed to answer an immediate and unanticipated question or need." (Craig S Mullins, "Database Administration", 2012)

"Any spontaneous or unplanned question or query. It is a query that consists of dynamically constructed SQL and is one capability in a data-driven DSS." (Ciara Heavin & Daniel J Power, "Decision Support, Analytics, and Business Intelligence" 3rd Ed., 2017)

🛢DBMS: Query (Definitions)

"1. A request for the retrieval of data with a select statement. 2. Any SQL statement that manipulates data." (Karen Paulsell et al, "Sybase SQL Server: Performance and Tuning Guide", 1996)

"A specific request for data retrieval, modification, or deletion." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"A SELECT statement." (Peter Gulutzan & Trudy Pelzer, "SQL Performance Tuning", 2002)

"A request for information based on the value of certain fields against a database or a data warehouse." (Margaret Y Chu, "Blissful Data ", 2004)

"A SQL SELECT statement that extracts data from a database." (Rod Stephens, "Beginning Database Design Solutions", 2008)

"The mechanism to get data out of a database. A query is comprised of constraints used to filter data out of the results, and defines the data elements to be included in the result set and possibly some mathematical computations, grouping, or sorting of the data." (Laura Reeves, "A Manager's Guide to Data Warehousing", 2009)

"A computing function that requests data from the database, stating the parameters and constraints for the request." (Paulraj Ponniah, "Data Warehousing Fundamentals for IT Professionals", 2010)

"(1) A SQL SELECT statement written and issued against a database. (2) To request data from a database." (Craig S Mullins, "Database Administration", 2012)

"An operation that retrieves data from tables or views. For example, SELECT * FROM employees is a query." (Oracle, "Database SQL Tuning Guide Glossary", 2013)

"A procedure executed by a computer program in search of qualified data" (Daniel Linstedt & W H Inmon, "Data Architecture: A Primer for the Data Scientist", 2014)

"A request for information from a database that is based on specific conditions: for example, a request for a list of all customers in a customer table whose balances are greater than USD1000. A component of certain SQL or XQuery statements that specifies a result set." (Sybase, "Open Server Server-Library/C Reference Manual", 2019)

"A type of question accepted by a database about the data it holds. A complex query may ask the database to select records according to some criteria, aggregate certain quantities across those records, etc. Many databases accept queries in the specialised language SQL or dialects of it." (Open Data Handbook)

🛢DBMS: Data Modeling (Definitions)

"A method of representing a database using a logical and graphical view. Data modeling can be performed using something as simple as pencil and paper or as involved as sophisticated software. The purpose of data modeling is to bridge the gap between the actual business process and the physical database implementation. The output of data modeling is usually a graphical representation of the data structures." (Microsoft Corporation, "Microsoft SQL Server 7.0 Data Warehouse Training Kit", 2000)

"A process of defining the entities, attributes, and relationships between the entities in preparation for creating the physical database." (Bob Bryla, "Oracle Database Foundations", 2004)

"The activity wherein subject areas of data and relationships between them are depicted in a diagram." (Margaret Y Chu, "Blissful Data ", 2004)

"A structured approach used to identify major components of an information system’s specifications. Data modeling enables you to promote data as a corporate asset to share across the enterprise, provide business professionals with a graphical display of their business rules and requirements, bridge the gap between business experts and technical experts, establish consensus/agreement, and build a stable data foundation." (Sharon Allen & Evan Terry, "Beginning Relational Data Modeling 2nd Ed.", 2005)

[Evolutionary data modeling:] "A process in which you model the data aspects of a system iteratively and incrementally, to ensure that the database schema evolves in step with the application code." (Pramod J Sadalage & Scott W Ambler, "Refactoring Databases: Evolutionary Database Design", 2006)

[evolutionary data modeling]: "Methodologies to iteratively and incrementally model database systems so that schema and applications evolve in a parallel way." (Vincenzo Deufemia et al, "Evolutionary Database: State of the Art and Issues", 2009)

[E-R Data Modeling:] "A popular data modeling technique used for representing business entities and the relationships among them." (Paulraj Ponniah, "Data Warehousing Fundamentals for IT Professionals", 2010)

"1.An analysis and design method, building data models to a) define and analyze data requirements, b) design logical and physical data structures that support these requirements, and c) define business and technical meta-data. 2.The act of creating a data model." (DAMA International, "The DAMA Dictionary of Data Management", 2011)

[enterprise data modeling:] "The development of a common consistent view and understanding of data entities and attributes, and their relationships across the enterprise." (DAMA International, "The DAMA Dictionary of Data Management", 2011)

"Data modeling is the ability and process of specifying and constructing complex data structures that represent specific semantics. In SQL, this can be performed with the ANSI-92 LEFT outer join operation that can inherently define and process complex data structures." (Michael M David & Lee Fesperman, "Advanced SQL Dynamic Data Modeling and Hierarchical Processing", 2013)

"A model that is used to either logically or physically organize the data elements in a database, including the definition of the data elements and of the relationships among the data elements for a specific industry, such as banking." (Jim Davis & Aiman Zeid, "Business Transformation: A Roadmap for Maximizing Organizational Insights", 2014)

"Considers data independently of the way the data are processed and of the components that process the data. A process used to define and analyze data requirements needed to support the business processes." (Adam Gordon, "Official (ISC)2 Guide to the CISSP CBK" 4th Ed., 2015)

"The process of architecting data objects and structures as they relate to a business or other context." (Jason Williamson, "Getting a Big Data Job For Dummies", 2015)

"The process of identifying and representing the definition, usage, and/or storage of data." (George Tillmann, "Usage-Driven Database Design: From Logical Data Modeling through Physical Schmea Definition", 2017)

"With dimensional data modeling or denormalization, data is collapsed, combined, or grouped together. Within dimensional data modeling, the concepts of facts (measures) and dimensions (context) are used. If dimensions are collapsed into single structures, the data model is also often called a star schema. If the dimensions are not collapsed, the data model is called snowflake. The dimensional models are typically seen within data warehouse systems." (Piethein Strengholt, "Data Management at Scale", 2020)

"A method that is used to define and analyze the data requirements that are needed in order to support the business functions of an enterprise. These data requirements are recorded as a conceptual data model with associated data definitions. Data modeling defines the relationships between data elements and structures." (Genesys) 

"The analysis of data objects using data modelling techniques to create insights from the data." (Analytics Insight)

🛢DBMS: Relationship (Definitions)

"A logical linkage between two entities that describes how the entities are associated with each other." (Owen Williams, "MCSE TestPrep: SQL Server 6.5 Design and Implementation", 1998)

"A link between tables that references the primary key in one table to a foreign key in another table. The relationship line is represented in a database diagram by a solid line if referential integrity between the tables is enforced, or a dashed line if referential integrity is not enforced for INSERT and UPDATE transactions. The endpoints of a relationship line show a primary key symbol to denote a primary-key-to-foreign-key relationship or an infinity symbol to denote the foreign key side of a one-to-many relationship." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"In database design, a property that exists between two (or sometimes more) entities. The property may represent a state, a behavior, an action, or some other logical combination and usually has a verb phrase or prepositional phrase as its name. In some modeling techniques, each relationship has two directions of interpretation; for example, in a library application, considering the book and book copy entities, a book may be owned as one or more book copies, and a book copy must be of exactly one book." (Bill Pribyl & Steven Feuerstein, "Learning Oracle PL/SQL", 2001)

"A link between tables that references the primary key in one table to a foreign key in another table. In English Query, a relationship is an association between entities that describes what those entities have to do with one another." (Anthony Sequeira & Brian Alderman, "The SQL Server 2000 Book", 2003)

"A relationship documents the business rule associating two entities. The relationship is used to describe how the two entities are naturally linked to each other." (Claudia Imhoff et al, "Mastering Data Warehouse Design", 2003)

"A connection between two entities that signifies the presence of a business rule." (Margaret Y Chu, "Blissful Data ", 2004)

"A connection between entities ties a parent entity to a child entity through the Primary Key in one entity to a Foreign Key in another." (Thomas Moore, "EXAM CRAM™ 2: Designing and Implementing Databases with SQL Server 2000 Enterprise Edition", 2005)

"A logical link between two entities that represents a business rule or constraint." (Sharon Allen & Evan Terry, "Beginning Relational Data Modeling" 2nd Ed., 2005)

"A social association or connection between two or more people." (Victor Isakov et al, "MCITP Administrator: Microsoft SQL Server 2005 Optimization and Maintenance (70-444) Study Guide", 2007)

"An association between two tables. For example, if an order contains several order items, there is a one-to-many relationship between Orders and OrderItems tables. Don't confuse this term with "relation."" (Rod Stephens, "Beginning Database Design Solutions", 2008)

"A link between tables that references the primary key in one table to a foreign key in another table." (Jim Joseph, "Microsoft SQL Server 2008 Reporting Services Unleashed", 2009)

"A real-world association among one or more entities. For example, “purchased” could be a relationship between customer and product." (Toby J Teorey, ", Database Modeling and Design" 4th Ed., 2010)

"The complete association among specific entity classes consisting of two or more relationship roles." (David C Hay, "Data Model Patterns: A Metadata Map", 2010)

"An association between entities." (Carlos Coronel et al, "Database Systems: Design, Implementation, and Management" 9th Ed., 2011)

"Defines how different entities are associated with each other. A relationship is defined by the keys: the primary key in the parent entity and the foreign key in the dependent entity." (Craig S Mullins, "Database Administration", 2012)

"The association of two or more entities; through this association, it expresses the business policy of the data model." (James Robertson et al, "Complete Systems Analysis: The Workbook, the Textbook, the Answers", 2013)

"A connection between two tables based on a shared field." (Faithe Wempen, "Computing Fundamentals: Introduction to Computers", 2015)

"Any connection between two or more variables. In research, there are many types of relationships, from simple contingencies to established causal relationships." (K  N Krishnaswamy et al, "Management Research Methodology: Integration of Principles, Methods and Techniques", 2016)

"A defined connection between the rows of a table or the rows of two tables. A relationship is the internal representation of a referential constraint." (Sybase, "Open Server Server-Library/C Reference Manual", 2019)

🛢DBMS: Joins (Definitions)

 "A basic operation in a relational system which links the rows in two or more tables by comparing the values in specified columns." (Karen Paulsell et al, "Sybase SQL Server: Performance and Tuning Guide", 1996)

"Process of combining data from two or more tables into a single operation." (Owen Williams, "MCSE TestPrep: SQL Server 6.5 Design and Implementation", 1998)

"As a verb, to combine the contents of two or more tables and produce a result set that incorporates rows and columns from each table. Tables are typically joined using data that they have in common. As a noun, join means the process or result of joining tables, as in the term inner join, which indicates a particular method of joining tables." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"The relational operator that allows data from multiple tables to be combined. A join matches rows of multiple tables based on columns with common values." (Peter Gulutzan & Trudy Pelzer, "SQL Performance Tuning", 2002)

"To combine two or more tables in a query to produce rows as a result of a comparison between columns in the tables." (Bob Bryla, "Oracle Database Foundations", 2004)

"The act of combining the data in two tables based on values found in each of the tables." (Thomas Moore, "EXAM CRAM™ 2: Designing and Implementing Databases with SQL Server 2000 Enterprise Edition", 2005)

"To combine data in two tables based on matching values found in each of the tables." (Thomas Moore, "MCTS 70-431: Implementing and Maintaining Microsoft SQL Server 2005", 2006)

"The matching of a record from one relational database table with a record in a second relational database table using a common column." (Reed Jacobsen & Stacia Misner, "Microsoft SQL Server 2005 Analysis Services Step by Step", 2006)

"Used to combine the contents of two or more tables. The most common join is an inner join. Other joins are left, right, full, and cross." (Darril Gibson, "MCITP SQL Server 2005 Database Developer All-in-One Exam Guide", 2008)

"A query that selects data from more than one table, usually using a JOIN or WHERE clause to indicate which records in the two tables go together." (Rod Stephens, "Beginning Database Design Solutions", 2008)

"A process or a result of combining the contents of two or more tables and producing a resultset that incorporates rows and columns from each table." (Jim Joseph, "Microsoft SQL Server 2008 Reporting Services Unleashed", 2009)

"A database operation used to merge data from two related tables that have common attributes." (Paulraj Ponniah, "Data Warehousing Fundamentals for IT Professionals", 2010)

"A relational algebra operation that combines two tables making new rows that are a combination of one row from each of the two source tables." (Jan L Harrington, "SQL Clearly Explained 3rd Ed. ", 2010)

"An operation in which the data from two tables is combined into a larger results table based on shared data values in each table." (Craig S Mullins, "Database Administration", 2012)

"To combine the contents of two or more tables and produce a result set that incorporates rows and columns from each table. Tables are typically joined using data that they have in common." (SQL Server 2012 Glossary, "Microsoft", 2012)

"A statement that retrieves data from multiple tables specified in the FROM clause of a SQL statement. Join types include inner joins, outer joins, and Cartesian joins." (Oracle, "Database SQL Tuning Guide Glossary", 2013)

"The process of merging two or more tables on the basis of a common key" (Daniel Linstedt & W H Inmon, "Data Architecture: A Primer for the Data Scientist", 2014)

"An SQL relational operation in which data can be retrieved from two tables, typically based on a join condition specifying join columns. See also equijoin, full outer join, inner join, left outer join, outer join, right outer join, star join." (Sybase, "Open Server Server-Library/C Reference Manual", 2019)

🛢DBMS: Entities (Definitions)

"A database or a database object that can be identified by a unique ID and that is backed by database pages." (Karen Paulsell et al, "Sybase SQL Server: Performance and Tuning Guide", 1996)

"An entity is a real-world object, referred to by a noun (person, place, thing, or idea), such as people, products, shipments, cities, and so on. Entities are semantic objects used in English Query." (Anthony Sequeira & Brian Alderman, "The SQL Server 2000 Book", 2003)

"The main object in an entity-relationship model, which can be deduced by case study examination. Entities represent the things, places, people, concepts, and things involved in a real-world situation, and contain within them properties or attributes that relate to them." (Thomas Moore, "EXAM CRAM™ 2: Designing and Implementing Databases with SQL Server 2000 Enterprise Edition", 2005)

"An object in our logical model that is used to store information about a 'thing of interest'." (Marilyn Miller-White et al, "MCITP Administrator: Microsoft® SQL Server™ 2005 Optimization and Maintenance 70-444", 2007)

"An encapsulation of data that is recognized by a business domain expert as a thing. Logical data entities can be tied to applications, repositories, and services and may be structured according to implementation considerations." (David Lyle & John G Schmidt, "Lean Integration", 2010)

 "(1) An element or set of elements that has a distinct, separate existence, although it need not  be a material existence. (2) An abstraction from the complexities of some domain." (International Qualifications Board for Business Analysis, 2011)

"Something that exists and is capable of being described. It is a person, place, thing, concept, or event about which your organization maintains facts." (Craig S Mullins, "Database Administration: The Complete Guide to DBA Practices and Procedures" 2nd Ed., 2012)

"An information structure that represents the data characteristic of an entity." (Microsoft) 

"An encapsulation of data that is recognized by a business domain expert as a thing. Logical data entities can be tied to applications, repositories, and services and may be structured according to implementation considerations." (TOGAF)

🛢DBMS: Fill Factor (Definitions)

"An option that specifies how full SQL Server should make each index page. The amount of empty space on an index page is important because when an index page fills up, the system must take time to split it to make room for new rows." (Patrick Dalton, "Microsoft SQL Server Black Book", 1997)

"Specifies to SQL server how full an index page should be." (Owen Williams, "MCSE TestPrep: SQL Server 6.5 Design and Implementation", 1998)

"An option used when creating an index to reserve free space on each page of the index. This option accommodates future expansion of table data and reduces the potential for page splits. It is a percentage from 0 through 100 that specifies how much of the data pages should be filled after the index is created." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"The fill factor value is a percentage from 0 to 100 that specifies how much to fill the data pages after the index is created. A fill factor value of 0 does not mean that index pages are left empty but rather that only the leaf pages are filled." (Microsoft Corporation, "Microsoft SQL Server 7.0 Data Warehouse Training Kit", 2000)

"Fill factor defines the amount of free space on each page of the index. You use fill factor when creating indexes. It accommodates future expansion of table data and reduces the potential for page splits." (Anthony Sequeira & Brian Alderman, "The SQL Server 2000 Book", 2003)

"An attribute of an index that defines the amount of free space allotted to each page of the index. FILLFACTOR can be used to allocate space for future expansion. FILLFACTOR is a value from 1 through 100 that specifies the percentage of the index page to be left empty." (Thomas Moore, "EXAM CRAM™ 2: Designing and Implementing Databases with SQL Server 2000 Enterprise Edition", 2005)

"The fill factor of an index indicates how much space to leave open for new data when the index is reorganized during maintenance." (Joseph L Jorden & Dandy Weyn, "MCTS Microsoft SQL Server 2005: Implementation and Maintenance Study Guide - Exam 70-431", 2006)

"An index option that identifies how full an index will be when it is created. For tables that have a lot of INSERTS, setting an indexes fill factor to something other than 0 (indicating 100 percent full) will prevent excessive page splits and the resulting fragmentation of indexes." (Darril Gibson, "MCITP SQL Server 2005 Database Developer All-in-One Exam Guide", 2008)

"An attribute of an index that defines how full the SQL Server Database Engine should make each page of the index." (Microsoft, "SQL Server 2012 Glossary", 2012)

🛢DBMS: Simple Protocol and RDF Query Language (Definitions)

"A simple query language for accessing RDF structures. As the majority of the query languages developed within a Web context, SPARQL is based on a strict ‘pattern-matching’ approach, which means that no inference facilities are directly associated with SPARQL. As the majority of the Web query languages, SPARQL makes use of a SQL-like format, employing then operators in the style of SELECT and WHERE." (Gian P Zarri, "RDF and OWL for Knowledge Management", 2011)

"An RDF query language standardized by the World Wide Web Consortium (W3C)." (DAMA International, "The DAMA Dictionary of Data Management", 2011)

"SPARQL is an RDF query language standardized by the World Wide Web Consortium (W3C). The acronym stands for SPARQL Protocol and RDF Query Language." (Michael Fellmann et al, "Supporting Semantic Verification of Process Models", 2012)

"An RDF query language; its name is a recursive acronym that stands for SPARQL Protocol and RDF Query Language." (Mahdi Gueffaz, "ScaleSem Approach to Check and to Query Semantic Graphs", 2015)

"An SQL-like, RDF query language and a recommendation by W3C, developed to manipulate and query the data stored in RDF format." (T R Gopalakrishnan Nair, "Intelligent Knowledge Systems", 2015)

"Is an RDF query language, that is, a semantic query language for databases, able to retrieve and manipulate data stored in Resource Description Framework format." (Fu Zhang et al, "A Review of Answering Queries over Ontologies Based on Databases", 2016)

"Is an RDF query language, that is, a semantic query language for databases, able to retrieve and manipulate data stored in Resource Description Framework format." (Fu Zhang & Haitao Cheng, "A Review of Answering Queries over Ontologies Based on Databases", 2016)

"SPARQL (Simple Protocol and RDF Query Language) is an RDF query language which is a W3C recommendation. SPARQL contains capabilities for querying required and optional graph patterns along with their conjunctions and disjunctions." (Hairong Wang et al, "Fuzzy Querying of RDF with Bipolar Preference Conditions", 2016)

"SPARQL can be used to express queries across diverse data sources, whether the data is stored natively as RDF or viewed as RDF via middleware. SPARQL contains capabilities for querying required and optional graph patterns along with their conjunctions and disjunctions." (Jingwei Cheng et al, "RDF Storage and Querying: A Literature Review", 2016)

"SPARQL (pronounced 'sparkle', a recursive acronym for SPARQL protocol and RDF query language) is an RDF query language, that is, a semantic query language for databases, able to retrieve and manipulate data stored in resource description framework (RDF) format." (Senthil K Narayanasamy & Dinakaran Muruganantham, "Effective Entity Linking and Disambiguation Algorithms for User-Generated Content (UGC)", 2018)

"SPARQL (Simple Protocol and RDF Query Language) is an RDF query language which is a W3C recommendation. SPARQL contains capabilities for querying required and optional graph patterns along with their conjunctions and disjunctions." (Zongmin Ma & Li Yan, "Towards Massive RDF Storage in NoSQL Databases: A Survey", 2019)

"It is a query language on documents described in RDF." (Antonio Sarasa-Cabezuelo & José Luis Fernández-Vindel, "A Model for the Creation of Academic Activities Based on Visits", 2020)

"The SPARQL query language is a structured language for querying RDF data in a declarative fashion. Its core function is subgraph pattern matching, which corresponds to finding all graph homomorphism in the data graph for a query graph." (Kamalendu Pal, "Ontology-Assisted Enterprise Information Systems Integration in Manufacturing Supply Chain", 2020)

"Query language used to access and retrieve RDF data distributed in different geographical locations." (Janneth Chicaiza, "Leveraging Linked Data in Open Education", 2021)

"It is used for querying data in RDF format, in a similar way that SQL is used to query relational databases. SPARQL is a standard created and maintained by the World Wide Web Consortium. SPARQL is useful for getting data out of linked databases as an alternative to a more specific API." (Data.Gov.UK)

"A query language similar to SQL, used for queries to a linked-data triple store." ("Open Data Handbook")

🛢DBMS: JavaScript Object Notation [JSON] (Definitions)

"A lightweight data-interchange format that is based on the object-literal notation of JavaScript. JSON is programming-language neutral but uses conventions from various languages." (IBM, "Informix Servers 12.1", 2014)

"Although originated from Javascript, the Javascript Object Notation is a language-independent and open data format that can be used to transmit human-readable text-based object information, across domains, using an attribute-value pair’s notation." (José Moura & Carlos Serrão, "Security and Privacy Issues of Big Data", 2015)

"JavaScript Object Notation, is an open standard format that uses human-readable text to transmit data objects consisting of attribute–value pairs. It is used primarily to transmit data between a server and web application, as an alternative to XML." (D P Misra & Alka Mishra, "Societal and Economical Impact on Citizens through Innovations Using Open Government Data: Indian Initiative on Open Government Data", 2015)

"The Javascript Object Notation (JSON) is a language-independent and open data format that can be used to transmit human-readable text-based object information, across domains, using an attribute-value pair’s notation and easy-to-access manner." (José Moura et al, "Intelligent Management and Efficient Operation of Big Data", 2015)

"JavaScript Object Notation (JSON) is a textual format for exchanging data that borrows its metamodel from the JavaScript programming language. Specifically, the JSON metamodel consists of two kinds of structures found in JavaScript: lists (called 'arrays' in JavaScript) and dictionaries (called 'objects' in JavaScript)." (Robert J Glushko, "The Discipline of Organizing: Professional Edition" 4th Ed., 2016)

"The JavaScript Object Notation is the binary format to represent data like list, map, date, Boolean and different precision numbers." (Maristela Holanda & Jane A Souza, "Query Languages in NoSQL Databases", Handbook of Research on Innovative Database Query Processing Techniques, 2016)

"Is a lightweight, text-based, open standard format for exchanging data between applications. Though it is originally derived from the JavaScript language, it is a language-neutral data format." (Venkat Gudivada & Dhana L Rao, "Database Systems for Big Data Storage and Retrieval", 2018)

"JSON (JavaScript Object Notation) is a binary and typed data model which is applied to represent data like list, map, date, Boolean as well as different precision numbers." (Zongmin Ma & Li Yan, "Towards Massive RDF Storage in NoSQL Databases: A Survey", 2019)

"JavaScript object notation is a lightweight data-interchange format which is easy for humans to read and write and for machines to parse and generate. It is based on a subset of the JavaScript programming language." (Amany Sarhan, "Cloud-Based IoT Platform: Challenges and Applied Solutions", 2019)

"A text-based open standard format for exchanging data between applications." (Gülay Ekren, "The Potential and Capabilities of NoSQL Databases for ERP Systems", 2020)

"A human-readable, plain text format for expressing structured data with support in many programming languages." (MongoDb)

"JavaScript Object Notation, a simple but powerful format for data. It can describe complex data structures, is highly machine-readable as well as reasonably human-readable, and is independent of platform and programming language, and is therefore a popular format for data interchange between programs and systems." (Open Data Handbook)

🛢DBMS: Concatenation (Definitions)

"Combine expressions to form longer expressions. The expressions can include any combination of binary or character strings, or column names." (Karen Paulsell et al, "Sybase SQL Server: Performance and Tuning Guide", 1996)

"Combining two or more character strings or expressions into a single character string or expression, or combining two or more binary strings or expressions into a single binary string or expression." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"A string operation consisting of assembling a string from two shorter strings." (Bill Pribyl & Steven Feuerstein, "Learning Oracle PL/SQL", 2001)

"The process of combining two or more character strings or expressions into a single character string or expression. Concatenation also refers to combining two or more binary strings or expressions into a single binary string or expression." (Anthony Sequeira & Brian Alderman, "The SQL Server 2000 Book", 2003)

"The process of combining two or more data elements into a single element. In Oracle SQL, concatenation can be accomplished by using the concatenation operator (a pair of vertical bars, ||) or the CONCAT function." (Bob Bryla, "Oracle Database Foundations", 2004)

"Combining two strings by placing one at the end of the other." (Jan L Harrington, "SQL Clearly Explained 3rd Ed. ", 2010)

"The process of combining two or more character strings or expressions into a single character string or expression, or combining two or more binary strings or expressions into a single binary string or expression." (Microsoft, "SQL Server 2012 Glossary", 2012)