🛢DBMS: Attribute (Definitions)

"A qualifier of an entity or a relation describing its character quantity, quality, degree, or extent. In database design, tables represent entities and columns represent attributes of those entities. For example, the title column represents an attribute of the entity titles." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

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

"An attribute is the lowest level of information relating to any entity. It models a specific piece of information or a property of a specific entity. Dimensional modeling has a more restrictive definition; it refers to information that describes the characteristics of a dimension." (Claudia Imhoff et al, "Mastering Data Warehouse Design", 2003)

"A data item that has been 'attached' to an entity. By doing this, a distinction can be made between the generic characteristics of the data item itself (for instance, data type and default documentation) and the entity-specific characteristics (for example, identifying and entity-specific documentation). It’s a distinct characteristic of an entity for which data is maintained. An attribute is a value that describes or identifies an entity, and an entity contains one or more attributes that characterize the entity as a whole. An entity example is Employee, and an attribute example is Employee Last Name." (Sharon Allen & Evan Terry, "Beginning Relational Data Modeling" 2nd Ed., 2005)

"A property that can assume values for entities or relationships. Entities can be assigned several attributes (for example, a tuple in a relationship consists of values). Some systems also allow relationships to have attributes as well." (William H Inmon, "Building the Data Warehouse", 2005)

"Information about a specific dimension member." (Reed Jacobsen & Stacia Misner, "Microsoft SQL Server 2005 Analysis Services Step by Step", 2006)

"The equivalent of a relational database field, used more often to describe a similar low-level structure in object structures." (Gavin Powell, "Beginning Database Design", 2006)

"The differing data items within a relation. An attribute is a named column of a relation." (S. Sumathi & S. Esakkirajan, "Fundamentals of Relational Database Management Systems", 2007)

"The formal database term for column." (Rod Stephens, "Beginning Database Design Solutions", 2008)

"Individual data element that is represented and stored in a dimension. Each attribute contains data relating to that dimension." (Laura Reeves, "A Manager's Guide to Data Warehousing", 2009)

"A primitive data element that provides descriptive detail about an entity; a data field or data item in a record. For example, lastname would be an attribute for the entity customer. Attributes may also be used as descriptive elements for certain relationships among entities." (Toby J Teorey, "Database Modeling and Design 4th Ed", 2010)

"A characteristic of an entity or object. An attribute has a name and a data type." (Carlos Coronel et al, "Database Systems: Design, Implementation, and Management" 9th Ed., 2011)

"Characteristic describing an entity. Also known as a field." (Linda Volonino & Efraim Turban, "Information Technology for Management 8th Ed", 2011)

"A single characteristic or additional piece of information (financial or non-financial) that exists in a database." (Microsoft, "SQL Server 2012 Glossary", 2012)

"An inherent fact, property, or characteristic describing an entity. Every attribute does one of three things: describes, identifies, or relates." (Craig S Mullins, "Database Administration", 2012)

"In modeling, an attribute represents a characteristic of an entity. Because of this use, attribute is sometimes understood as a data element (which is a component piece of a data used to represent an entity), or a field (which is part of a system used to display or intake data), or a column (which is a place in a table to store a defined characteristic of a represented entity, that is, to store values associated with data elements)." (Laura Sebastian-Coleman, "Measuring Data Quality for Ongoing Improvement ", 2012)

"A data element that describes an entity or a relationship. Each attribute applies to every occurrence of its entity or relationship." (James Robertson et al, "Complete Systems Analysis: The Workbook, the Textbook, the Answers", 2013)

"In the context of information, a descriptor that is not usually associated with a numerical value. Some examples are bad, excellent, red, green, tall, small, wide, far, heavy, fast, portrait, and scenic." (Kenneth A Shaw, "Integrated Management of Processes and Information", 2013)

"A value of data that is distinguishable from other values" (Daniel Linstedt & W H Inmon, "Data Architecture: A Primer for the Data Scientist", 2014)

"The property or characteristic of an object that can be distinguished quantitatively or qualitatively by human or automated means." (David Sutton, "Information Risk Management: A practitioner’s guide", 2014)

"Characteristics of an object we capture in a catalog or model for data management purposes. Example: last name is an attribute of a person." (Gregory Lampshire, "The Data and Analytics Playbook", 2016)

🛢DBMS: Data Replication (Definitions)

 "Duplication of table schema and data or stored procedure definitions and calls from a source database to a destination database, usually on separate servers." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"A process that copies and distributes data and database objects from one database to another and then synchronizes information between databases for consistency." (Anthony Sequeira & Brian Alderman, "The SQL Server 2000 Book", 2003)

"The duplication of I/O from one set of disks to another similar set, on a file level." (Tom Petrocelli, "Data Protection and Information Lifecycle Management", 2005)

"A set of technologies for copying and distributing data and database objects from one database to another and then synchronizing between databases to maintain consistency." (Thomas Moore, "MCTS 70-431: Implementing and Maintaining Microsoft SQL Server 2005", 2006)

"This is a process that copies data from one database to another." (Joseph L Jorden & Dandy Weyn, "MCTS Microsoft SQL Server 2005: Implementation and Maintenance Study Guide - Exam 70-431", 2006)

"Process of copying data and database objects from one data source to another across a network. This is done to synchronize two databases or to maintain a remote copy of a database." (Sara Morganand & Tobias Thernstrom , "MCITP Self-Paced Training Kit : Designing and Optimizing Data Access by Using Microsoft SQL Server 2005 - Exam 70-442", 2007)

"A process whereby information is published from a database server and sent to one or more subscribers. Data may be transferred proactively by the publisher or requested by the subscribers. See also publishand- subscribe." (Robert D Schneider & Darril Gibson, "Microsoft SQL Server 2008 All-in-One Desk Reference For Dummies", 2008)

"A group of technologies within SQL Server 2005 that are used to copy and distribute data and database objects from one database to another. Data is then regularly synchronized to maintain consistency. Replication uses a publishing metaphor with Publishers (data source), Distributors (process responsible for replicating the data and/or objects), and Subscribers (data target)." (Darril Gibson, "MCITP SQL Server 2005 Database Developer All-in-One Exam Guide", 2008)

"A feature allowing multiple database servers to share the same data, thereby ensuring redundancy and facilitating load balancing." (MongoDb, "Glossary", 2008)

"A process whereby information is published from a database server and sent to one or more subscribers. Data may be transferred proactively by the publisher or requested by the subscribers." (Robert D. Schneider and Darril Gibson, "Microsoft SQL Server 2008 All-In-One Desk Reference For Dummies", 2008)

"A set of techniques and technologies to make and then maintain a copy of data from a source database. Different approaches support different synchronization and performance requirements." (Allen Dreibelbis et al, "Enterprise Master Data Management", 2008)

"The process of storing data in multiple databases while ensuring that it remains consistent. For example, one database might contain a master copy of the data and other satellite databases might hold read-only copies to let clerks view data quickly without impacting the main database." (Rod Stephens, "Beginning Database Design Solutions", 2008)

"Carrying out an identical transaction on two copies of the data in sequence." (David G Hill, "Data Protection: Governance, Risk Management, and Compliance", 2009)

"A method for creating copies of the database, either in real time or in a deferred mode." (Paulraj Ponniah, "Data Warehousing Fundamentals for IT Professionals", 2010)

"The storage of duplicated database fragments at multiple sites on a DDBMS. Duplication of the fragments is transparent to the end user. Used to provide fault tolerance and performance enhancements." (Carlos Coronel et al, "Database Systems: Design, Implementation, and Management" 9th Ed., 2011)

"The copying of data from a data source to one or more target environments based on rules." (Craig S Mullins, "Database Administration", 2012)

"The process of copying content and/or configuration settings from one location, generally a server node, to another. Replication is done to ensure synchronization or fault tolerance." (Microsoft, "SQL Server 2012 Glossary", 2012)

"The process of maintaining a defined set of data in more than one location. Replication involves copying designated changes for one location (a source) to another (a target) and synchronizing the data in both locations." (Sybase, "Open Server Server-Library/C Reference Manual", 2019)

🛢DBMS: Snapshot (Definitions)

"A snapshot is a view of information at a particular point in time." (Claudia Imhoff et al, "Mastering Data Warehouse Design", 2003)

"A database dump or the archiving of data out of a database as of some moment in time." (William H Inmon, "Building the Data Warehouse", 2005)

"A database snapshot is a moment-in-time recording of a database and keeps track of every change made to a database from the moment the snapshot was taken. This method often prevents user mistakes as an add-on to fault-tolerance." (Joseph L Jorden & Dandy Weyn, "MCTS Microsoft SQL Server 2005: Implementation and Maintenance Study Guide - Exam 70-431", 2006)

"A feature of SQL Server 2005 that enables you to indefinitely store the state of the database at a particular point in time." (Marilyn Miller-White et al, "MCITP Administrator: Microsoft® SQL Server™ 2005 Optimization and Maintenance 70-444", 2007)

"A new feature of SQL Server 2005 where a snapshot of a database can be created at any given time to preserve the state of the database. The snapshot can be queried if desired and/or the entire database can be restored from the snapshot." (Darril Gibson, "MCITP SQL Server 2005 Database Developer All-in-One Exam Guide", 2008)

"The state of an object, a system, or a collection of attributes regarding a state at a particular point in time." (DAMA International, "The DAMA Dictionary of Data Management", 2011)

"A read-only, static view of a database at the moment of snapshot creation." (Microsoft, "SQL Server 2012 Glossary", 2012)

"A copy of a data structure at some point in time" (Nell Dale et al, "Object-Oriented Data Structures Using Java" 4th Ed., 2016)

"A record of the current state of the database environment." (Sybase, "Open Server Server-Library/C Reference Manual", 2019)

🛢DBMS: Physical Design (Definitions)

"The phase of a database design following the logical design that identifies the actual database tables and index structures used to implement the logical design." (Ralph Kimball & Margy Ross, "The Data Warehouse Toolkit" 2nd Ed , 2002)

"The actual tables, columns, indexes, and other data structures used to store information in a SQL Server database. Development projects typically progress from a logical database design to a physical database design." (Robert D. Schneider and Darril Gibson, "Microsoft SQL Server 2008 All-In-One Desk Reference For Dummies", 2008)

"The actual tables, columns, indexes, and other data structures used to store information in a SQL Server database. Development projects typically progress from a logical database design to a physical database design. See also logical design." (Robert D Schneider & Darril Gibson, "Microsoft SQL Server 2008 All-in-One Desk Reference For Dummies", 2008)

"The step in the database life cycle involved with the physical structure of the data; that is, how it will be stored, retrieved, and updated efficiently. In particular, it is concerned with issues of table indexing and data clustering on secondary storage devises (disk)." (Toby J Teorey, ", Database Modeling and Design 4th Ed", 2010)

"A stage of database design that maps the data storage and access characteristics of a database. Since these characteristics are a function of the types of devices supported by the hardware, the data access methods supported by the system (and the selected DBMS) physical design is both hardware- and software-dependent. See also physical model." (Carlos Coronel et al, "Database Systems: Design, Implementation, and Management 9th Ed", 2011)

"Physical design structures (PDSs) include items such as indexes, indexed VIEWs, and partitioning. These are referenced in the Database Engine Tuning Advisor, which is used to evaluate a database and can recommend the implementation of different types of physical design structures for better performance." (Darril Gibson, "MCITP SQL Server 2005 Database Developer All-in-One Exam Guide", 2008)

"States how the system will perform its functions, with actual physical specifications." (Linda Volonino & Efraim Turban, "Information Technology for Management 8th Ed", 2011)

🛢DBMS: Graph Database (Definitions)

"Databases that use graph structures with nodes, edges and characteristics to depict and store information." (Swati V Chande, "Cloud Database Systems: NoSQL, NewSQL, and Hybrid", 2014)

"A graph database is any storage system that uses graph structures with nodes and edges, to represent and store data." (Jaroslav Pokorný, "Graph Databases: Their Power and Limitations", 2015)

"Makes use of graph structures with nodes and edges to manage and represent data. Unlike a relational database, a graph database does not rely on joins to connect data sources." (Judith S Hurwitz, "Cognitive Computing and Big Data Analytics", 2015)

"A database type that uses vertices and edges to store information." (Kornelije Rabuzin, "Query Languages for Graph Databases" 2018)

"A graph database is a database that uses graph structures for semantic queries with nodes, edges and properties to represent and store data." (Data Wold)

"A graph database is a type of database where there is no hierarchy - all data is stored as a series of nodes and edges (links between nodes). Typically each node of the graph represents a thing or the value of a property, and each edge represents a property - a particular type of relationship between the two nodes that it joins. This makes it easier to query the database based on relationships and it makes for a very flexible data structure that is easy to alter or extend. Graph databases are very useful for storing datasets that are complex with lots of connections." (Data.Gov.UK)

"Optimized database technology to store, manage, and access inter data to answer complex questions." (Forrester)

"A graph database, also called a graph-oriented database, is a type of NoSQL database that uses graph theory to store, map and query relationships." (The Open Group)

"they use graph structures (a finite set of ordered pairs or certain entities), with edges, properties and nodes for data storage. It provides index-free adjacency, meaning that every element is directly linked to its neighbour element." (Analytics Insight)

🛢DBMS: Logical Design (Definitions)

 "An implementation-independent design that models the entities, relationships, and attributes in a database." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"An implementation-independent design that models the entities, relationships, and attributes in a database." (Microsoft Corporation, "Microsoft SQL Server 7.0 Data Warehouse Training Kit", 2000)

"The phase of a database design concerned with identifying the relationships among the data elements. Contrast with Physical design." (Ralph Kimball & Margy Ross, "The Data Warehouse Toolkit" 2nd Ed., 2002)

"A part of database design that is concerned with modeling the business requirements and data." (S. Sumathi & S. Esakkirajan, "Fundamentals of Relational Database Management Systems", 2007)

"The abstract design and structure of your relational database." (Robert D Schneider & Darril Gibson, "Microsoft SQL Server 2008 All-in-One Desk Reference For Dummies", 2008)

"The abstract design and structure of your relational database. Focusing on the high-level objects and their interrelationships, this is usually generated during the analysis phase of most projects. It then serves as a guideline for creating the actual implementation of your SQL Server database." (Robert D. Schneider and Darril Gibson, "Microsoft SQL Server 2008 All-In-One Desk Reference For Dummies", 2008)

"The steps in the database life cycle involved with the design of the conceptual data model (schema), schema integration, transformation to SQL tables, and table normalization; the design of a database in terms of how the data is related, but without regard to how it will be stored." (Toby J Teorey, ", Database Modeling and Design" 4th Ed., 2010)

"A stage in the design phase that matches the conceptual design to the requirements of the selected DBMS and is, therefore, software-dependent. It is used to translate the conceptual design into the internal model for a selected database management system, such as DB2, SQL Server, Oracle, IMS, Informix, Access, and Ingress." (Carlos Coronel et al, "Database Systems: Design, Implementation, and Management" 9th Ed., 2011)

🛢DBMS: Nondeterministic Function (Definitions)

"A function that may generate different outputs each time it is run, even if the inputs are always the same." (Peter Gulutzan & Trudy Pelzer, "SQL Performance Tuning", 2002)

"A function is non-deterministic if it can return different results when provided with the same input. The RAND function is non-deterministic because it returns a different randomly generated number each time it is called." (Thomas Moore, "EXAM CRAM™ 2: Designing and Implementing Databases with SQL Server 2000 Enterprise Edition", 2005)

"A characteristic of a function that means the function can return different results when provided with the same input. For example, the RAND function is nondeterministic because it returns a different randomly generated number each time it is called." (Thomas Moore, "MCTS 70-431: Implementing and Maintaining Microsoft SQL Server 2005", 2006)

"Nondeterministic functions return different values when they’re invoked with the same arguments." (Joseph L Jorden & Dandy Weyn, "MCTS Microsoft SQL Server 2005: Implementation and Maintenance Study Guide - Exam 70-431", 2006)

"Typically refers to functions such as nondeterministic functions. A nondeterministic function returns different results when called with the same input values. As an example, GETDATE() would return different results at different times. Indexed views can not include nondeterministic functions." (Darril Gibson, "MCITP SQL Server 2005 Database Developer All-in-One Exam Guide", 2008)

"An application whose state of execution cannot be predicted is said to be nondeterministic. Since the operating system schedules threads for execution on processor resources and there are too many factors that influence the OS scheduling, the state of execution of a concurrent application cannot be reliably predicted. Typically, incorrect use of nondeterminism in concurrent applications will be evidenced by the application returning different results from the same inputs." (Clay Breshears, "The Art of Concurrency", 2009)

"Exhibiting a lack of deterministic behavior, so results can vary from run to run of an algorithm. See more in the definition for deterministic." (Michael McCool et al, "Structured Parallel Programming", 2012)

"A user-defined function whose result is not solely dependent on the values of the input arguments. That is, successive invocation with the same argument value can produce a different answer." (Sybase, "Open Server Server-Library/C Reference Manual", 2019)

🛢DBMS: Deterministic Function (Definitions)

"A function that always generates the same outputs, given the same inputs." (Peter Gulutzan & Trudy Pelzer, "SQL Performance Tuning", 2002)

"A function is deterministic if it always returns the same output when presented with the same input." (Thomas Moore, "EXAM CRAM™ 2: Designing and Implementing Databases with SQL Server 2000 Enterprise Edition", 2005)

"A characteristic of a function that means the function always returns the same output when presented with the same input." (Thomas Moore, "MCTS 70-431: Implementing and Maintaining Microsoft SQL Server 2005", 2006)

"Deterministic functions return the same value each time they’re invoked with the same arguments." (Joseph L Jorden & Dandy Weyn, "MCTS Microsoft SQL Server 2005: Implementation and Maintenance Study Guide - Exam 70-431", 2006)

"Whether a function always returns the same output given the same inputs." (Marilyn Miller-White et al, "MCITP Administrator: Microsoft® SQL Server™ 2005 Optimization and Maintenance 70-444", 2007)

"A deterministic function is one which, given a specific set of inputs, will always produce the same result. The SQL Server decryption functions are an example of deterministic functions. SQL Server’s symmetric encryption functions, however, generate a random IV so the result is nondeterministic." (Michael Coles & Rodney Landrum, , "Expert SQL Server 2008 Encryption", 2008)

"Typically refers to functions such as deterministic functions. A deterministic function always returns the same result when called with the same input values. Indexed VIEWs require any functions used within the indexed VIEW to be deterministic. As a comparison, see nondeterministic." (Darril Gibson, "MCITP SQL Server 2005 Database Developer All-in-One Exam Guide", 2008)

"a computation situation in which the execution time of an action sequence is known precisely." (Bruce P Douglass, "Real-Time Agility: The Harmony/ESW Method for Real-Time and Embedded Systems Development", 2009)

"Given the same inputs, a deterministic application will present the same (observable) results each and every time." (Clay Breshears, "The Art of Concurrency", 2009)

"A deterministic algorithm is an algorithm that behaves predictably. Given a particular input, a deterministic algorithm will always produce the same output. The definition of what is the “same” may be important due to limited precision in mathematical operations and the likelihood that optimizations including parallelization will rearrange the order of operations. These are often referred to as “rounding” differences, which result when the order of mathematical operations to compute answers differs between the original program and the final concurrent program. Concurrency is not the only factor that can lead to non-deterministic algorithms but in practice it is often the cause. Use of programming models with sequential semantics and eliminating data races with proper access controls will generally eliminate non-determinism other than the 'rounding' differences." (Michael McCool et al, "Structured Parallel Programming", 2012)

"Having a predictable value with a very narrow range of variance. As a result, deterministic values do not require the use of probability distributions to describe their behavior in business analysis methods or decisions and can usually be represented by a constant value." (Kenneth A Shaw, "Integrated Management of Processes and Information", 2013)

"A user-defined function with a result that is dependent on the values of the input arguments. Successive invocations with the same input values produce the same answer." (Sybase, "Open Server Server-Library/C Reference Manual", 2019)

🛢DBMS: Database Catalog [DBC] (Definitions)

"Tables provided in the Model database." (Owen Williams, "MCSE TestPrep: SQL Server 6.5 Design and Implementation", 1998)

"The set of system tables in a database that describes the database contents." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"A database catalog contains the definition of all the objects in the database, as well as the definition of the database." (Anthony Sequeira & Brian Alderman, "The SQL Server 2000 Book", 2003)

"This is an object in a database that is used to organize full-text indexes." (Joseph L Jorden & Dandy Weyn, "MCTS Microsoft SQL Server 2005: Implementation and Maintenance Study Guide - Exam 70-431", 2006)

"A directory storing metadata." (Rod Stephens, "Beginning Database Design Solutions", 2008)

"A group of schemas, usually composed of all schemas handled by a single DBMS." (Jan L Harrington, "SQL Clearly Explained 3rd Ed. ", 2010)

"The part of a database that contains the definition of all the objects in the database, as well as the definition of the database." (Microsoft, "SQL Server 2012 Glossary", 2012)

"Structured list made up of comparable objects, used as a reference." (Gilbert Raymond & Philippe Desfray, "Modeling Enterprise Architecture with TOGAF", 2014)

"A collection of tables and views that contains descriptions of objects such as tables, views, and indexes." (Sybase, "Open Server Server-Library/C Reference Manual", 2019)

🛢DBMS: Database Objects [DBO] (Definitions)

"One of the components of a database: table, view, index, procedure, trigger, column, default, or rule." (Karen Paulsell et al, "Sybase SQL Server: Performance and Tuning Guide", 1996)

"One of the components of a database: a table, index, trigger, view, key, constraint, default, rule, user-defined data type, or stored procedure." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"Any structure or entity that exists in an Oracle database, such as a table, index, PL/SQL program, or view. For a list of database objects owned by the current user, look in the data dictionary's USEROBJECTS view." (Bill Pribyl & Steven Feuerstein, "Learning Oracle PL/SQL", 2001)

"Any database component. It could be a table, index, trigger, view, key, constraint, default, rule, user-defined data type, or stored procedure in a database." (Anthony Sequeira & Brian Alderman, "The SQL Server 2000 Book", 2003)

"Any object in a database, such as a table, a view, an index, a stored procedure, or a trigger." (Carlos Coronel et al, "Database Systems: Design, Implementation, and Management" 9th Ed., 2011)

"An object that exists in an installation of a database system, such as an instance, a database, a database partition group, a buffer pool, a table, or an index." (Sybase, "Open Server Server-Library/C Reference Manual", 2019)

"Any of the various items included in a database including tables, views, diagrams, and so on." (Victor Isakov et al, "MCITP Administrator: Microsoft SQL Server 2005 Optimization and Maintenance (70-444) Study Guide", 2007)

 

🛢DBMS: Dirty Read (Definitions)

"Occurs when one transaction modifies a row, and then a second transaction reads that row before the first transaction commits the change. If the first transaction rolls back the change, the information read by the second transaction becomes invalid." (Karen Paulsell et al, "Sybase SQL Server: Performance and Tuning Guide", 1996)

"Reads that contain uncommitted data. For example, transaction 1 changes a row. Transaction 2 reads the changed row before transaction 1 commits the change. If transaction 1 rolls back the change, transaction 2 reads a row that is considered to have never existed." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"A problem arising with concurrent transactions. The Dirty Read problem occurs when a transaction reads a row that has been changed but not committed by another transaction. The result is that Transaction #2's work is based on a change that never really happened. You can avoid Dirty Read by using an isolation level of READ COMMITTED or higher." (Peter Gulutzan & Trudy Pelzer, "SQL Performance Tuning", 2002)

"A problem with uncontrolled concurrent use of a database where a transaction acts on data that have been modified by an update transaction that hasn't committed and is later rolled back." (Jan L Harrington, "Relational Database Design and Implementation" 3rd Ed., 2009)

"The problem that arises when a transaction reads the same data more than once, including data modified by concurrent transactions that are later rolled back." (Jan L Harrington, "SQL Clearly Explained" 3rd Ed., 2010)

"A read that contains uncommitted data." (Microsoft, "SQL Server 2012 Glossary", 2012)

"A read request that does not involve any locking mechanism. This means that data can be read that might later be rolled back resulting in an inconsistency between what was read and what is in the database." (IBM, "Informix Servers 12.1", 2014)

 "A transaction reads data that has been written by another transaction that has not been committed yet. Oracle Database never permits dirty reads." (Oracle)

"An operation that retrieves unreliable data, data that was updated by another transaction but not yet committed. It is only possible with the isolation level known as read uncommitted. This kind of operation does not adhere to the ACID principle of database design. It is considered very risky, because the data could be rolled back, or updated further before being committed; then, the transaction doing the dirty read would be using data that was never confirmed as accurate." (MySQL)

"Reads that contain uncommitted data." (Microsoft Technet)

🛢DBMS: Trace (Definitions)

"The process of recording the sequence in which the statements in a program are executed and, optionally, the values of the program variables used in the statements." (Sybase, "Glossary", 2005)

"The SQL Profiler method for recording server events." (Thomas Moore, "EXAM CRAM™ 2: Designing and Implementing Databases with SQL Server 2000 Enterprise Edition", 2005)

"This is a record of data that has been captured about events in Profiler." (Joseph L Jorden & Dandy Weyn, "MCTS Microsoft SQL Server 2005: Implementation and Maintenance Study Guide - Exam 70-431", 2006)

"A collection of events and related performance data returned by SQL Server’s database engine." (Victor Isakov et al, "MCITP Administrator: Microsoft SQL Server 2005 Optimization and Maintenance (70-444) Study Guide", 2007)

"A trace is a collection of events and data. SQL Profiler is used to collect and monitor events. Creating a trace is sometimes referred to as capturing events." (Darril Gibson, "MCITP SQL Server 2005 Database Developer All-in-One Exam Guide", 2008)

"A collection of events and data returned by the Database Engine." (Microsoft, "SQL Server 2012 Glossary", 2012)

"A record of the processing of a computer program or transaction. The information collected from a trace can be used to assess problems and performance." (IBM, "Informix Servers 12.1", 2014)

"In DB2 replication, a facility that is used to collect monitoring, auditing, and performance data for the Capture program, the Q Capture program, the Apply program, the Q Apply program, or the Replication Alert Monitor." (Sybase, "Open Server Server-Library/C Reference Manual", 2019)

🛢DBMS: Data Synchronization (Definitions)

"In replication, the process that ensures the publication and destination tables contain the same schema and data. This process must occur before a subscription server can receive replicated transactions from an article or a publication." (Patrick Dalton, "Microsoft SQL Server Black Book", 1997)

"Refers to the process in which the article or articles subscribed to on a subscription server are initially synchronized with the original article or articles on the publication server." (Owen Williams, "MCSE TestPrep: SQL Server 6.5 Design and Implementation", 1998)

[automatic synchronization:] "Synchronization that is accomplished automatically by SQL Server when a server initially subscribes to a publication. A snapshot of the table data and schema are written to files for transfer to the Subscriber. The table schema and data are transferred by the distribution agent. No operator intervention is required." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"The process of maintaining the same schema and data in a publication at a Publisher and in the replica of a publication at a Subscriber. See also initial snapshot." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"The process of ensuring that the publication and destination tables contain the same schema and data. This process must occur before a new Subscriber can receive replicated transactions from a publication. It is also called initial synchronization." (Microsoft Corporation, "Microsoft SQL Server 7.0 Data Warehouse Training Kit", 2000)

"Synchronization is the process in replication of maintaining the same schema and data at a Publisher and at a Subscriber." (Anthony Sequeira & Brian Alderman, "The SQL Server 2000 Book", 2003)

"Integrating, matching, or linking data from disparate sources." (Linda Volonino & Efraim Turban, "Information Technology for Management" 8th Ed., 2011)

"The continuous harmonization of data attribute values between two or more different systems, with the end result being the data attribute values are the same in all of the systems." (DAMA International, "The DAMA Dictionary of Data Management", 2011)

[initial synchronization:] "The first synchronization for a subscription, during which system tables and other objects that are required by replication, and the schema and data for each article, are copied to the Subscriber." (Microsoft, "SQL Server 2012 Glossary", 2012)

"The process by which a satellite downloads and runs the same DB2 database commands, operating system commands, and SQL statements from the satellite control server as the other members of its group download and then reports the results to the satellite control server." (Sybase, "Open Server Server-Library/C Reference Manual", 2019)

"A form of embedded middleware that allows applications to update data on two systems so that the data sets are identical. These services can run via a variety of different transports but typically require some application-specific knowledge of the context and notion of the data being synchronized." (Gartner)

"Data synchronization is the effort to ensure that, once data leaves a system or storage entity, it does not fall out of harmony with its source, thereby creating inconsistency in the data record." (Information) [source] 

 "1. In replication, the process of data and schema changes being propagated between the Publisher and Subscribers after the initial snapshot has been applied at the Subscriber. 2. In database mirroring, when a mirroring session starts or resumes, the process in which log records of the principal database that have accumulated on the principal server are sent to the mirror server, which writes these log records to disk as quickly as possible to catch up with the principal server." (Microsoft Technet)

"The process of keeping selected data in multiple data sources in agreement." (Microsoft Technet)

"The term, Synchronization, refers to the process of replicating the changes made to documents on one database to the same documents in a second instance of that database." (Couchbase)

🛢DBMS: Distributed Database (Definitions)

"A database implemented on a network in which the component partitions are distributed over various nodes of the network. Depending on the specific update and retrieval traffic, distributing the database can enhance overall performance significantly." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"A database located at more than one site." (S. Sumathi & S. Esakkirajan, "Fundamentals of Relational Database Management Systems", 2007)

"A database with pieces stored on multiple computers on a network." (Rod Stephens, "Beginning Database Design Solutions", 2008)

"A database where portions of the database are stored on computers at physically distributed locations. The entire database is the sum of all the parts." (Jan L Harrington, "Relational Database Design and Implementation" 3rd Ed., 2009)

"A logically related database that is stored over two or more physically independent sites." (Carlos Coronel et al, "Database Systems: Design, Implementation, and Management" 9th Ed., 2011)

"A database whose tables are stored on different but interconnected computing systems." (Sybase, "Open Server Server-Library/C Reference Manual", 2019)

🛢DBMS: Relational Database Management System [RDBMS] (Definitions)

"A system that organizes data into related rows and columns. SQL Server is a relational database management system." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"A database, built on a model of data as existing in rows and columns, intended to embody the theoretical foundations of relational data that were originally defined by Dr. E. F. Codd at IBM. The Oracle server is one example, along with IBM's DB2, Microsoft's SQL Server, and mySQL." (Bill Pribyl & Steven Feuerstein, "Learning Oracle PL/SQL", 2001)

"Database management system based on the relational model that supports the full range of standard SQL. Uses a series of joined tables with rows and columns to organize and store data." (Ralph Kimball & Margy Ross, "The Data Warehouse Toolkit 2nd Ed ", 2002)

"A system that organizes data into related rows and columns. SQL Server is a relational database management system." (Anthony Sequeira & Brian Alderman, "The SQL Server 2000 Book", 2003)

"A system used to create, edit, and manage relational databases." (Johannes Link & Peter Fröhlich, "Unit Testing in Java", 2003)

"The controlling software for databases in which data is organized into related objects within a database rather than tied to a file. Each of these objects is related to another in some way." (Thomas Moore, "EXAM CRAM™ 2: Designing and Implementing Databases with SQL Server 2000 Enterprise Edition", 2005)

"A system that uses a database that contains tables with data. The management system part is the part allowing you access to that database, and the power to manipulate both the database and the data contained within it." (Gavin Powell, "Beginning Database Design", 2006)

"Software that organizes manipulates and retrieves data stored in a relational database." (S. Sumathi & S. Esakkirajan, "Fundamentals of Relational Database Management Systems", 2007)

"A system that organizes data into related rows and columns. SQL Server is an RDBMS." (Jim Joseph, "Microsoft SQL Server 2008 Reporting Services Unleashed", 2009)

"A database management system whose architecture is based on Dr. E. F. Codd’s relational theory. That is, it stores data in terms of simple, two dimensional tables." (David C Hay, "Data Model Patterns: A Metadata Map", 2010)

"Type of DBMS that uses SQL to store data in related tables." (Martin Oberhofer et al, "The Art of Enterprise Information Architecture", 2010)

"A collection of programs that manages a relational database. The RDBMS software translates a user’s logical requests (queries) into commands that physically locate and retrieve the requested data. A good RDBMS also creates and maintains a data dictionary (system catalog) to help provide data security, data integrity, concurrent access, easy access, and system administration to the data in the database through a query language (SQL) and application programs." (Carlos Coronel et al, "Database Systems: Design, Implementation, and Management" 9th Ed., 2011)

"A database system that organizes data into related rows and columns as specified by a relational model." (Microsoft, "SQL Server 2012 Glossary", 2012)

"A database management system that organizes data in defined tables. " (Marcia Kaufman et al, "Big Data For Dummies", 2013)

"A collection of hardware and software that organizes and provides access to a relational database." (Sybase, "Open Server Server-Library/C Reference Manual", 2019)