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  2. Write-ahead logging - Wikipedia

    en.wikipedia.org/wiki/Write-ahead_logging

    The changes are first recorded in the log, which must be written to stable storage, before the changes are written to the database. [2] The main functionality of a write-ahead log can be summarized as: [3] Allow the page cache to buffer updates to disk-resident pages while ensuring durability semantics in the larger context of a database system.

  3. Aggregate function - Wikipedia

    en.wikipedia.org/wiki/Aggregate_function

    In the MapReduce framework, these steps are known as InitialReduce (value on individual record/singleton set), Combine (binary merge on two aggregations), and FinalReduce (final function on auxiliary values), [5] and moving decomposable aggregation before the Shuffle phase is known as an InitialReduce step, [6] Decomposable aggregation ...

  4. MongoDB - Wikipedia

    en.wikipedia.org/wiki/MongoDB

    MongoDB is a source-available, cross-platform, document-oriented database program. Classified as a NoSQL database product, MongoDB uses JSON-like documents with optional schemas. Released in February 2009 by 10gen (now MongoDB Inc.), it supports features like sharding, replication, and ACID transactions (from version 4.0).

  5. Data aggregation - Wikipedia

    en.wikipedia.org/wiki/Data_aggregation

    The information is packaged into aggregate reports and then sold to businesses, as well as to local, state, and government agencies. This information can also be useful for marketing purposes. In the United States, many data brokers' activities fall under the Fair Credit Reporting Act (FCRA) which regulates consumer reporting agencies .

  6. Enhanced entity–relationship model - Wikipedia

    en.wikipedia.org/wiki/Enhanced_entity...

    The enhanced entity–relationship (EER) model (or extended entity–relationship model) in computer science is a high-level or conceptual data model incorporating extensions to the original entity–relationship (ER) model, used in the design of databases.

  7. Database design - Wikipedia

    en.wikipedia.org/wiki/Database_design

    The following steps are suggestion of the data modeling process for Microsoft Access, a relational DBMS. Determine the purpose of the database – This helps prepare for the remaining steps. Find and organize the information required – Gather all of the types of information to record in the database, such as product name and order number.

  8. Query by Example - Wikipedia

    en.wikipedia.org/wiki/Query_by_Example

    Query by Example (QBE) is a database query language for relational databases. It was devised by Moshé M. Zloof at IBM Research during the mid-1970s, in parallel to the development of SQL . [ 1 ] It is the first graphical query language, using visual tables where the user would enter commands, example elements and conditions.

  9. Algorithms for Recovery and Isolation Exploiting Semantics

    en.wikipedia.org/wiki/Algorithms_for_Recovery...

    Write-ahead logging: Any change to an object is first recorded in the log, and the log must be written to stable storage before changes to the object are written to disk. Repeating history during Redo: On restart after a crash, ARIES retraces the actions of a database before the crash and brings the system back to the exact state that it was in ...

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