🛢DBMS: Normalization (Definitions)

"Normalization is the database design process of discarding repeating groups, minimizing redundancy, eliminating composite keys for partial dependency, and separating non-key attributes. Various levels of normalization and various rules or tests have been formalized for performing normalization." (Microsoft Corporation, "Microsoft SQL Server 7.0 Data Warehouse Training Kit", 2000)

"The process of transforming database designs into logical structures by following rules and principles of relational database theory. Different 'normal forms' exist, each further reducing both redundancy and the possibility of update anomalies. 'Third normal form' is a design in which all the attributes of each row 'depend on the key, the whole key, and nothing but the key'." (Bill Pribyl & Steven Feuerstein, "Learning Oracle PL/SQL", 2001)

"The process of designing a database so that its tables follow the rules specified by relational theory. In practice, this usually means that all database tables are in third normal form." (Peter Gulutzan & Trudy Pelzer, "SQL Performance Tuning", 2002)

"Normalization is a method for ensuring that the data model meets the objectives of accuracy, consistency, simplicity, nonredundancy, and stability. It is a physical database design technique that applies mathematical rules to the relational data model to identify and reduce insertion, updating, or deletion anomalies." (Claudia Imhoff et al, "Mastering Data Warehouse Design", 2003)

"A formal approach in data modeling that examines and validates attributes and their entities in the Logical data model. The purpose of data normalization is to ensure that each attribute belongs to the entity to which it has been assigned, that redundant storage of information is minimized, and that storage anomalies are eliminated." (Sharon Allen & Evan Terry, "Beginning Relational Data Modeling 2nd Ed.", 2005)

"Developed by Dr. E. F. Codd in 1970, database normalization is the process of simplifying data and database design to achieve maximum performance and simplicity. This process involves the removing of useless and redundant data." (Thomas Moore, "EXAM CRAM™ 2: Designing and Implementing Databases with SQL Server 2000 Enterprise Edition", 2005)

"A process by which a relational schema design is adjusted to reduce the possibility of storing data redundantly. As a schema is normalized, attributes that contain repeating values are moved into new tables and replaced by a foreign key. This process requires analyzing and understanding the dependencies among attributes and key columns. There are several degrees of normalization, which formally describe the extent to which redundancies have been removed. Third normal form (3NF) is widely accepted as the optimal relational design for a transaction system. A star schema design is often referred to as denormalized, although it is actually in second normal form." (Christopher Adamson, "Mastering Data Warehouse Aggregates", 2006)

"The organization of data to reduce redundancy by creating many linked tables so that a value is stored in only one place." (Reed Jacobsen & Stacia Misner, "Microsoft SQL Server 2005 Analysis Services Step by Step", 2006)

"The process of simplifying the structure of data. Normalization increases granularity and Granularity is the scope of a definition for any particular thing. The more granular a data model is, the easier it becomes to manage, up to a point, depending, of course, on the application of the database model." (Gavin Powell, "Beginning Database Design", 2006)

"A formal process of removing redundancy from a database design by separating it into children tables from the parent table." (Victor Isakov et al, "MCITP Administrator: Microsoft SQL Server 2005 Optimization and Maintenance (70-444) Study Guide", 2007)

"Logical design process in which data is separated into multiple, related tables. The process allows databases to perform optimally." (Sara Morganand & Tobias Thernstrom , "MCITP Self-Paced Training Kit : Designing and Optimizing Data Access by Using Microsoft SQL Server 2005 - Exam 70-442", 2007)

"The design process for generating entity specifications to minimize both data redundancy and update anomalies." (S. Sumathi & S. Esakkirajan, "Fundamentals of Relational Database Management Systems", 2007)

"A series of database design recommendations that dictate how information should be dispersed among tables as well as how these tables should relate." (Robert D. Schneider and Darril Gibson, "Microsoft SQL Server 2008 All-In-One Desk Reference For Dummies", 2008)

"The process of transforming the database's structure to minimize the changes of certain kinds of data anomalies." (Rod Stephens, "Beginning Database Design Solutions", 2008)

"The process of designing relations to adhere to increasingly stringent sets of rules to avoid problems with poor database design." (Jan L Harrington, "Relational Database Design and Implementation" 3rd Ed., 2009)

"The process of breaking up a table into smaller tables to eliminate problems with unwanted loss of data (the egregious side effects of losing data integrity) from the deletion of records and inefficiencies associated with multiple data updates." (Toby J Teorey, ", Database Modeling and Design" 4th Ed., 2010)

"The process, originally articulated by Dr. E. F. Codd in his relational theory, for organizing data to reduce redundancy to the minimum possible. It involves guaranteeing that each attribute in a 'relation' (table or entity class) is truly an attribute of that relation and none other. The process involves organizing data to follow the constraints of at least first normal form, second normal form, and third normal form. Additional value is found in Boyce-Codd normal form, fourth normal form, and fifth normal form." (David C Hay, "Data Model Patterns: A Metadata Map", 2010)

"A process that assigns attributes to entities in such a way that data redundancies are reduced or eliminated." (Carlos Coronel et al, "Database Systems: Design, Implementation, and Management 9th Ed", 2011)

"The process of organizing data to minimize redundancy and remove ambiguity. In simple terms, normalization is the process of identifying the one best place each fact belongs." (Craig S Mullins, "Database Administration", 2012)

"The process of organizing data at its detailed level into according to its existence criteria" (Daniel Linstedt & W H Inmon, "Data Architecture: A Primer for the Data Scientist", 2014)

"The process of restructuring a data model by reducing its relations to their simplest forms. It is a key step in the task of building a logical relational database design. Normalization helps avoid redundancies and inconsistencies in data. An entity is normalized if it meets a set of constraints for a particular normal form (first normal form, second normal form, and so on)." (Sybase, "Open Server Server-Library/C Reference Manual", 2019)

🛢DBMS: Transactions (Definitions)

"A mechanism for ensuring that a set of actions is treated as a single unit of work." (Karen Paulsell et al, "Sybase SQL Server: Performance and Tuning Guide", 1996)

"A series of SQL statements that constitute an atomic unit of work: either all are committed as a unit or they are all rolled back as a unit. A transaction begins with the first statement since the last transaction end and finishes with a transaction end (either COMMIT or ROLLBACK) statement." (Peter Gulutzan & Trudy Pelzer, "SQL Performance Tuning", 2002)

"A group of database operations combined into a logical unit of work that is either wholly committed or rolled back. A transaction is atomic, consistent, isolated, and durable." (Anthony Sequeira & Brian Alderman, "The SQL Server 2000 Book", 2003)

"A logical unit of work consisting of one or more SQL statements that must all succeed or all fail to keep the database in a logically consistent state. A transfer of funds from a bank account is a logical transaction, in that both the withdrawal from one account and the deposit to another account must succeed for the transaction to succeed." (Bob Bryla, "Oracle Database Foundations", 2004)

"A series of database operations that should be treated as a single atomic operation so either they all occur or none of them occur." (Rod Stephens, "Beginning Database Design Solutions", 2008)

"One or more SQL statements that make up a unit of work performed against the database. Either all the statements in a transaction are committed as a unit or all the statements are rolled back as a unit." (John Goodson & Robert A Steward, "The Data Access Handbook", 2009)

"A group of database operations combined into a logical unit of work that is either wholly committed or rolled back. A transaction is atomic, consistent, isolated, and durable." (Jim Joseph, "Microsoft SQL Server 2008 Reporting Services Unleashed", 2009)

"An atomic unit of work with respect to recovery and consistency." (Craig S Mullins, "Database Administration: The Complete Guide to DBA Practices and Procedures" 2nd Ed, 2012)

"An atomic unit of work with respect to recovery and consistency." (Craig S Mullins, "Database Administration", 2012)

"Each individual purchase. Each time customers swipe a card, shell out cash, or press the purchase confirmation button online, a transaction takes place. This data often is referred to as transaction log (T-log) data." (Brittany Bullard, "Style and Statistics", 2016)

🛢DBMS: Entity-Relationship Model [ERM] (Definitions)

"A common way to organize, think about, or discuss the elements of the 'real world' that a database design will represent, by dividing them into entities and relationships." (Bill Pribyl & Steven Feuerstein, "Learning Oracle PL/SQL", 2001)

"A type of conceptual data model that represents structured data in terms of entities and relationships. An entity-relationship diagram can be used to represent information objects and their relationships visually. Because the constructs used in the entity-relationship model can easily be transformed into relational tables, this type of model is often used in database design." (J P Getty Trust, "Introduction to Metadata" 2nd Ed., 2008)

"A data model that is used to represent data in its purest form and to define relationships between different entities." (Laura Reeves, "A Manager's Guide to Data Warehousing", 2009)

"A technique for representing entity relationships that is independent of any specific data model and any specific software." (Jan L Harrington, "Relational Database Design and Implementation" 3rd Ed., 2009)

"A conceptual data model involving entities, relationships among entities, and attributes of those entities." (Toby J Teorey, ", Database Modeling and Design" 4th Ed., 2010)

"A data model developed by P. Chen in 1975. It describes relationships (1:1, 1:M, and M:N) among entities at the conceptual level with the help of ER diagrams." (Carlos Coronel et al, "Database Systems: Design, Implementation, and Management" 9th Ed., 2011)

"An abstract and conceptual representation of data. Entity-relationship model consists of a set of entities, characterized by attributes and linked by relationships." (International Qualifications Board for Business Analysis, "Standard glossary of terms used in Software Engineering", 2011)

"1.Generally, a record-based data modeling scheme that focuses on entities and relationships in the presentation of data model diagrams, thus suppressing the display of attributes. A true ER model allows multi-valued data items and repeating groups of items (nested relations, thus violating first normal form), retains M:N relationships, attributed relationships, subtypes/supertypes, ternary and higher-order relationships, none of which can be represented directly in a relational data model. A true ER model generally excludes (defers) the representation of entity identifiers and foreign keys. Originally proposed and named by Peter Chen (1976). 2.In relational modeling, the most popular style of data model, defining entities and the business relationships between the entities. Some more detailed models include also some of the attributes of these entities, usually those involved in the relationships as keys." (DAMA International, "The DAMA Dictionary of Data Management", 2011)

"A data management approach that graphically represents relationships between data. This allows developers to create new relationships between data sources without complex programming." (Marcia Kaufman et al, "Big Data For Dummies", 2013)

"A logical view of data within a system, representing the entities in the system as well as relationships among the entities, attributes of the entities, and attributes of the relationships." (IEEE 610.5-1990)

🛢DBMS: Pass-Through Query (Definitions)

"A query that is passed uninterpreted to an external server for evaluation. The result set returned by a pass-through query can be used in the FROM clause of a query like an ordinary base table." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"A query that is passed through uninterrupted to an external database engine." (Marilyn Miller-White et al, "MCITP Administrator: Microsoft® SQL Server™ 2005 Optimization and Maintenance 70-444", 2007)

"An SQL-specific query you use to send commands directly to an ODBC database server." (Microsoft, "SQL Server 2012 Glossary", 2012)

🛢DBMS: Record (Definitions)

"A group of related fields (columns) of information treated as a unit. A record is more commonly called a row in a SQL database." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"A row in a database table." (Bill Pribyl & Steven Feuerstein, "Learning Oracle PL/SQL", 2001)

"An aggregation of values of data organized by their relation to a common key." (William H Inmon, "Building the Data Warehouse", 2005)

"In relational databases, a single instance in a table. In the context of hierarchical and network databases, a record is a data structure." (Sharon Allen & Evan Terry, "Beginning Relational Data Modeling" 2nd Ed., 2005)

"A repetition of a field structure across a table. Records repeat field structure in a table, where each repeated field can (and sometimes should) have a different value. Tables are divided into fields and records. Fields impose structure and datatype specifics onto each of the field values, in each record." (Gavin Powell, "Beginning Database Design", 2006)

"This is a group of related fields containing information about a single entity." (Joseph L Jorden & Dandy Weyn, "MCTS Microsoft SQL Server 2005: Implementation and Maintenance Study Guide - Exam 70-431", 2006)

"A grouping of information typically returned from a query or other database operation. It can consist of data from only one table or be an aggregation of information dispersed among many tables" (Robert D Schneider and Darril Gibson, "Microsoft SQL Server 2008 All-In-One Desk Reference For Dummies", 2008)

"In a file processing system, a collection of data that describes one instance of an entity." (Jan L Harrington, "Relational Database Design and Implementation" 3rd Ed., 2009)

"A group of data items treated as a unit by an application; a row in a database table." (Toby J Teorey, ", Database Modeling and Design" 4th Ed., 2010)

"A collection of related (logically connected) fields." (Carlos Coronel et al, "Database Systems: Design, Implementation, and Management 9th Ed", 2011)

"Related characters combined into a field or related fields, such as vendor name, address, and account data." (Linda Volonino & Efraim Turban, "Information Technology for Management 8th Ed", 2011)

"A set of related data values in a file or stream, often associated with a unique key field." (Jon Orwant et al, "Programming Perl" 4th Ed., 2012)

"The physical representation of data about an instance in a flat file." (Craig S Mullins, "Database Administration: The Complete Guide to DBA Practices and Procedures 2nd Ed", 2012)

"A unit of data that typically contains keys and attributes" (Daniel Linstedt & W H Inmon, "Data Architecture: A Primer for the Data Scientist", 2014)

"A collection of related data items." (Adam Gordon, "Official (ISC)2 Guide to the CISSP CBK" 4th Ed., 2015)

"A collection of related fields in a table. In Excel, each record goes into a separate row." (E C Nelson & Stephen L Nelson, "Excel Data Analysis For Dummies ", 2015)

"A row in a table, storing information about a specific person, place, or thing." (Faithe Wempen, "Computing Fundamentals: Introduction to Computers", 2015)

"In a relational database, a single set of values in a table. For example, a particular student’s data would be contained in a record in the Students table. Also called rows or tuples." (Rod Stephens, "Beginning Software Engineering", 2015)

"A collection of related fields that make up a single database entry" (Nell Dale & John Lewis, "Computer Science Illuminated" 6th Ed., 2015)

🛢DBMS: Row (Definitions)

"A set of related columns that describes a specific entity. Also called record." (Karen Paulsell et al, "Sybase SQL Server: Performance and Tuning Guide", 1996)

"A data structure that is a collection of elements (columns), each with its own name and type. A row can be accessed as a collective unit of elements, or the elements can be accessed individually. A row is equivalent to a record." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"In a relational database table, a primary key value plus the associated values of each non-key column. The number of rows usually varies over time." (Bill Pribyl & Steven Feuerstein, "Learning Oracle PL/SQL", 2001)

"A record in a relational table." (Ralph Kimball & Margy Ross, "The Data Warehouse Toolkit 2nd Ed ", 2002)

"The collection of elements that form a horizontal line in the table. Each row in the table represents a single occurrence of the object modeled by the table and stores the values for all the attributes of that object." (Anthony Sequeira & Brian Alderman, "The SQL Server 2000 Book", 2003)

"A group of one or more data elements in a database table that describes a person, place, or thing." (Bob Bryla, "Oracle Database Foundations", 2004)

"A single instance in a table. This is also called a record." (Sharon Allen & Evan Terry, "Beginning Relational Data Modeling" 2nd Ed., 2005)

"A group of related column values in a table. The corresponding formal database term is tuple." (Rod Stephens, "Beginning Database Design Solutions", 2008)

"An individual entry from a given table. For example, a table may contain details about thousands of customers; a specific customer’s data will be found in one row. See also record." (Robert D Schneider & Darril Gibson, "Microsoft SQL Server 2008 All-in-One Desk Reference For Dummies", 2008)

"A horizontal line in the table that contains all attributes of a single object modeled in the table." (Jim Joseph, "Microsoft SQL Server 2008 Reporting Services Unleashed", 2009)

"In relational theory, a set of values for a specified set of attributes." (David C Hay, "Data Model Patterns: A Metadata Map", 2010)

"A group of data items treated as a unit by an application; a record; a tuple in relational database terminology." (Toby J Teorey, ", Database Modeling and Design" 4th Ed., 2010)

"A set of column values describing one logical instance in a relational database table. Technically called a tuple in relational calculus. Equivalent to a record in a flat file." (DAMA International, "The DAMA Dictionary of Data Management", 2011)

"A set of column values describing one logical instance in a table." (Craig S Mullins, "Database Administration", 2012)

"The horizontal component of a table, consisting of a sequence of values, one for each column of the table." (Sybase, "Open Server Server-Library/C Reference Manual", 2019)

🛢DBMS: One-to-Many Relationship (Definitions)

"An instance of an entity is associated with zero or several instances of another entity." (Owen Williams, "MCSE TestPrep: SQL Server 6.5 Design and Implementation", 1998)

"A relationship between two tables in which a single row in the first table can be related to one or more rows in the second table, but a row in the second table can be related only to one row in the first table. A typical one-to-many relationship is between the publishers table and the titles table in the pubs sample database, in which each publisher can be related to several titles, but each title can be related to only one publisher." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"A logical data relationship in which the value of one data element can exist in combination with many values of another data element, but not vice versa." (Ralph Kimball & Margy Ross, "The Data Warehouse Toolkit" 2nd Ed., 2002)

"A relationship type between tables where one row in a given table is related to many other rows in a child table. The reverse condition, however, is not true. A given row in a child table is related to only one row in the parent table." (Bob Bryla, "Oracle Database Foundations", 2004)

"These relationships exist when a single instance of an entity (the parent entity) relates to many instances of another entity (the child entity). One-to-many relationships are the most common relationships in the real world." (Thomas Moore, "EXAM CRAM™ 2: Designing and Implementing Databases with SQL Server 2000 Enterprise Edition", 2005)

"The relationship between two tables dictated by having one record in one table, and many related records in another table." (Gavin Powell, "Beginning Database Design", 2006)

"The use of one key value from a dimension table in many rows of a fact table." (Reed Jacobsen & Stacia Misner, "Microsoft SQL Server 2005 Analysis Services Step by Step", 2006)

"A relationship between two tables in which a single row in the first table can be related to one or more rows in the second table, but a row in the second table can be related only to one row in the first table." (S. Sumathi & S. Esakkirajan, "Fundamentals of Relational Database Management Systems", 2007)

"Used in a relational database to denote that a single row in the parent table can be related to one or more rows in the related child table but that a row in the child table can be related to only a single row in the referenced parent table." (Marilyn Miller-White et al, "MCITP Administrator: Microsoft SQL Server 2005 Optimization and Maintenance 70-444", 2007)

"A relationship where one object of one type may correspond to many objects of another type. For example, one INSTRUCTOR may teach many COURSEs but each COURSE has only one INSTRUCTOR." (Rod Stephens, "Beginning Database Design Solutions", 2008)

"One of three types of relationships (associations among two or more entities) that are used by data models. In a 1:M relationship, one entity instance is associated with many instances of the related entity." (Carlos Coronel et al, "Database Systems: Design, Implementation, and Management" 9th Ed., 2011)

"A link between two entities in which the cardinality of one side of the relationship is one and the other is multiple." (Craig S Mullins, "Database Administration", 2012)

"A relationship in which the connected field is unique in one table and not unique in the other table." (Faithe Wempen, "Computing Fundamentals: Introduction to Computers", 2015)

"A relationship between two entities in a database such that one instance of an entity can be related to many instances of a second entity and the second entity can be related to only one instance of the first." (Jan L Harrington, "Relational Database Design and Implementation" 3rd Ed., 2009)

🛢DBMS: Domain Integrity (Definitions)

"Describes the inclusion of attribute rules (for example, maximum discount and minimum order quantity) within the design of a database." (Owen Williams, "MCSE TestPrep: SQL Server 6.5 Design and Implementation", 1998)

"Integrity that enforces valid entries for a given column. Domain integrity is enforced by restricting the type (through data types), the format (through CHECK constraints and rules), or the range of possible values (through REFERENCE and CHECK constraints, and rules)." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"Domain integrity enforces the validity of entries for a given column. The mechanism, such as the CHECK constraint, can restrict the possible data values by data type, format, or range of values allowed." (Anthony Sequeira & Brian Alderman, "The SQL Server 2000 Book", 2003)

"A relational database integrity mechanism that enforces the validity of data at the column level." (Marilyn Miller-White et al, "MCITP Administrator: Microsoft® SQL Server™ 2005 Optimization and Maintenance 70-444", 2007)

"The validity of entries for a specific column of data." (Microsoft, "SQL Server 2012 Glossary", 2012)

🛢DBMS: Subquery (Definitions)

"A SELECT statement nested inside another SELECT, INSERT, UPDATE, or DELETE statement, or inside another subquery." (Patrick Dalton, "Microsoft SQL Server Black Book", 1997)

"A SELECT statement that is usually a part of a larger SQL statement; a query nested inside a SELECT, INSERT, UPDATE, or DELETE statement." (Owen Williams, "MCSE TestPrep: SQL Server 6.5 Design and Implementation", 1998)

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

"A query that is embedded in a main, or parent, query and used to assist in filtering the result set from a query." (Bob Bryla, "Oracle Database Foundations", 2004)

"A nested query that returns information to an outer query, thereby helping the outer query correctly identify results." (Robert D. Schneider and Darril Gibson, "Microsoft SQL Server 2008 All-In-One Desk Reference For Dummies", 2008)

"A complete SELECT statement that is part of another SELECT." (Jan L Harrington, "SQL Clearly Explained 3rd Ed. ", 2010)

"A SELECT statement that contains one or more subqueries." (SQL Server 2012 Glossary, "Microsoft", 2012)

"A query nested within another SQL statement. Unlike implicit queries, subqueries use a SELECT statement to retrieve data." (Oracle, "Database SQL Tuning Guide Glossary", 2013)

"A form of a full-select that is enclosed within parentheses and used as a component of a query." (Sybase, "Open Server Server-Library/C Reference Manual", 2019)

🛢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)