🛢DBMS: Merge Replication (Definitions)

"A type of replication that allows sites to make autonomous changes to replicated data and, at a later time, merge changes made at all sites. Merge replication does not guarantee transactional consistency." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"A type of replication that allows sites to make autonomous changes to replicated data, and at a later time, merge changes and resolve conflicts when necessary." (Anthony Sequeira & Brian Alderman, "The SQL Server 2000 Book", 2003)

"The process of transferring data from the Publisher to the Subscriber, allowing the Publisher and Subscriber to update data while connected or disconnected and then merging the updates after they both are connected. Merge replication begins with a snapshot. Thereafter, no data is replicated until the Publisher and Subscriber do a "merge." The merge can be scheduled or done via an ad-hoc request. Merge replication's main benefit is that it supports subscribers who are not on the network much of the time. Transactions, which are committed, however, may be rolled back as the result of conflict resolution." (Thomas Moore, "EXAM CRAM™ 2: Designing and Implementing Databases with SQL Server 2000 Enterprise Edition", 2005)

"A replication type that relies on DML operations being captured from both the published database and the subscriber database(s) and automatically synchronized. Typically starts with a snapshot of the publication. Uses triggers to track subsequent changes made at either the publisher or subscriber." (Victor Isakov et al, "MCITP Administrator: Microsoft SQL Server 2005 Optimization and Maintenance (70-444) Study Guide", 2007)

"A replication strategy used when multiple subscribers are also acting as publishers. In other words, the data is updated from multiple sources." (Darril Gibson, "MCITP SQL Server 2005 Database Developer All-in-One Exam Guide", 2008)

"A type of replication that allows sites to make autonomous changes to replicated data, and at a later time, merge changes and resolve conflicts when necessary." (Microsoft Technet)

"Merge replication is a method for copying and distributing data and database objects from one SQL Server database to another followed by synchronizing the databases for consistency." (Idera) [source]

🛢DBMS: Snapshot Replication (Definitions)

"A type of replication that takes a snapshot of current data in a publication at a Publisher and replaces the entire replica at a Subscriber on a periodic basis, in contrast to publishing changes when they occur." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"A type of replication that distributes data exactly as it appears at a specific moment in time and does not monitor for modifications made to the data." (Anthony Sequeira & Brian Alderman, "The SQL Server 2000 Book", 2003)

"A type of replication wherein data and database objects are distributed by copying published items via the Distributor and on to the Subscriber exactly as they appear at a specific moment in time. Snapshot replication provides the distribution of both data and structure (tables, indexes, and so on) on a scheduled basis. It may be thought of as a 'whole table refresh'. No updates to the source table are replicated until the next scheduled snapshot." (Thomas Moore, "EXAM CRAM™ 2: Designing and Implementing Databases with SQL Server 2000 Enterprise Edition", 2005)

"Replication type that relies on a snapshot of the entire article (table) to be automatically sent from a published database to the subscriber database(s). Distributes data exactly as it appears at a given time." (Marilyn Miller-White et al, "MCITP Administrator: Microsoft® SQL Server™ 2005 Optimization and Maintenance 70-444", 2007)

"Replication type that relies on a snapshot of the entire article (table) to be automatically sent from a published database to the subscriber database(s). Distributes data exactly as it appears at a given time." (Victor Isakov et al, "MCITP Administrator: Microsoft SQL Server 2005 Optimization and Maintenance (70-444) Study Guide", 2007)

"Replication of data taken at a moment of time. With snapshot replication, the entire data set is replicated at the same time." (Darril Gibson, "MCITP SQL Server 2005 Database Developer All-in-One Exam Guide", 2008)

"A replication in which data is distributed exactly as it appears at a specific moment in time and does not monitor for updates to the data." (Microsoft, 2012)

"Snapshot replication distributes data exactly as it appears at a specific moment in time and does not monitor for updates to the data." (Microsoft Technet)

🛢DBMS: Transactional Replication (Definitions)

"A type of replication that marks selected transactions in the Publisher's database transaction log for replication and then distributes them asynchronously to Subscribers as incremental changes, while maintaining transactional consistency." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"A type of replication where an initial snapshot of data is applied at Subscribers, and then when data modifications are made at the Publisher, the individual transactions are captured and propagated to Subscribers." (Anthony Sequeira & Brian Alderman, "The SQL Server 2000 Book", 2003)

"A type of replication where data and database objects are distributed by first applying an initial snapshot at the Subscriber and then later capturing transactions made at the Publisher and propagating them to individual Subscribers. Transactional replication, as with all replication types, begins with a synchronizing snapshot. After the initial synchronization, transactions, which are committed at the Publisher, are automatically replicated to the Subscribers." (Thomas Moore, "EXAM CRAM™ 2: Designing and Implementing Databases with SQL Server 2000 Enterprise Edition", 2005)

"A replication type that relies on DML operations being captured from a published database and automatically sent to the subscriber database(s). Starts with a snapshot of the publication. Incremental changes both in data and schema at the source are replicated to the destination as they occur." (Marilyn Miller-White et al, "MCITP Administrator: Microsoft® SQL Server™ 2005 Optimization and Maintenance 70-444", 2007)

"Replication that starts with a snapshot and then keeps the Subscribers up-to-date by using the transaction log. Transactions are recorded on the Publisher, distributed to the Subscribers, and then applied to keep the Subscribers up-to-date." (Darril Gibson, "MCITP SQL Server 2005 Database Developer All-in-One Exam Guide", 2008)

"A type of replication that typically starts with a snapshot of the publication database objects and data." (SQL Server 2012 Glossary, "Microsoft", 2012)

"In SQL Replication, a type of processing in which every transaction is replicated to the target table when it is committed in the source table." (Sybase, "Open Server Server-Library/C Reference Manual", 2019)

 "A type of replication that typically starts with a snapshot of the publication database objects and data." (Microsoft Technet)

🛢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)