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  2. Schema matching - Wikipedia

    en.wikipedia.org/wiki/Schema_matching

    The terms schema matching and mapping are often used interchangeably for a database process. For this article, we differentiate the two as follows: schema matching is the process of identifying that two objects are semantically related (scope of this article) while mapping refers to the transformations between the objects. For example, in the ...

  3. Bitmap index - Wikipedia

    en.wikipedia.org/wiki/Bitmap_index

    This implementation is a hybrid between the basic bitmap index (without compression) and the list of Row Identifiers (RID-list). Overall, the index is organized as a B+tree. When the column cardinality is low, each leaf node of the B-tree would contain long list of RIDs. In this case, it requires less space to represent the RID-lists as bitmaps.

  4. Database index - Wikipedia

    en.wikipedia.org/wiki/Database_index

    A database index is a data structure that improves the speed of data retrieval operations on a database table at the cost of additional writes and storage space to maintain the index data structure. Indexes are used to quickly locate data without having to search every row in a database table every time said table is accessed.

  5. Soundex - Wikipedia

    en.wikipedia.org/wiki/Soundex

    Soundex is the most widely known of all phonetic algorithms (in part because it is a standard feature of popular database software such as IBM Db2, PostgreSQL, [2] MySQL, [3] SQLite, [4] Ingres, MS SQL Server, [5] Oracle, [6] ClickHouse, [7] Snowflake [8] and SAP ASE. [9]) Improvements to Soundex are the basis for many modern phonetic algorithms.

  6. Microsoft Access - Wikipedia

    en.wikipedia.org/wiki/Microsoft_Access

    Access Database, used for addins (Access 2, 95, 97), previously used for workgroups (Access 2).mda Access Blank Database Template (2003 and earlier).mdn Access Access (SQL Server) detached database (2000).mdf Protected Access Database, with compiled VBA and macros (2003 and earlier).mde Access lock files (associated with .mdb).ldb

  7. Second normal form - Wikipedia

    en.wikipedia.org/wiki/Second_normal_form

    Second normal form (2NF), in database normalization, is a normal form. A relation is in the second normal form if it fulfills the following two requirements: It is in first normal form. It does not have any non-prime attribute that is functionally dependent on any proper subset of any candidate key of the relation (i.e. it lacks partial ...

  8. Inverted index - Wikipedia

    en.wikipedia.org/wiki/Inverted_index

    The purpose of an inverted index is to allow fast full-text searches, at a cost of increased processing when a document is added to the database. [2] The inverted file may be the database file itself, rather than its index. It is the most popular data structure used in document retrieval systems, [3] used on a large scale for example in search ...

  9. Database - Wikipedia

    en.wikipedia.org/wiki/Database

    Formally, a "database" refers to a set of related data accessed through the use of a "database management system" (DBMS), which is an integrated set of computer software that allows users to interact with one or more databases and provides access to all of the data contained in the database (although restrictions may exist that limit access to particular data).