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  2. Order by - Wikipedia

    en.wikipedia.org/wiki/Order_by

    The sort criteria can be expressions, including column names, user-defined functions, arithmetic operations, or CASE expressions. The expressions are evaluated and the results are used for the sorting, i.e., the values stored in the column or the results of the function call. ORDER BY is the only way to sort the

  3. MonetDB - Wikipedia

    en.wikipedia.org/wiki/MonetDB

    MonetDB is an open-source column-oriented relational database management system (RDBMS) originally developed at the Centrum Wiskunde & Informatica (CWI) in the Netherlands.It is designed to provide high performance on complex queries against large databases, such as combining tables with hundreds of columns and millions of rows.

  4. Select (SQL) - Wikipedia

    en.wikipedia.org/wiki/Select_(SQL)

    Previous Page: sort the data in the reverse order, select only the first {rows} rows, where the {unique_key} is less than {first_val} (the value of the {unique_key} of the first row in the current page), and sort the result in the correct order; Read and send to display all the rows read from the database

  5. Standard column family - Wikipedia

    en.wikipedia.org/wiki/Standard_column_family

    The standard column family is a NoSQL object that contains columns of related data. It is a tuple (pair) that consists of a keyvalue pair, where the key is mapped to a value that is a set of columns. In analogy with relational databases, a standard column family is as a "table", each keyvalue pair being a "row". [1]

  6. Sort-merge join - Wikipedia

    en.wikipedia.org/wiki/Sort-merge_join

    The sort-merge join (also known as merge join) is a join algorithm and is used in the implementation of a relational database management system.. The basic problem of a join algorithm is to find, for each distinct value of the join attribute, the set of tuples in each relation which display that value.

  7. Entity–attribute–value model - Wikipedia

    en.wikipedia.org/wiki/Entity–attribute–value...

    To represent substructure, one incorporates a special EAV table where the value column contains references to other entities in the system (i.e., foreign key values into the objects table). To get all the information on a given object requires a recursive traversal of the metadata, followed by a recursive traversal of the data that stops when ...

  8. Database index - Wikipedia

    en.wikipedia.org/wiki/Database_index

    An index normally includes a "key" or direct link to the original row of data from which it was copied, to allow the complete row to be retrieved efficiently. Some databases extend the power of indexing by letting developers create indexes on column values that have been transformed by functions or expressions.

  9. Data cleansing - Wikipedia

    en.wikipedia.org/wiki/Data_cleansing

    Set-Membership constraints: The values for a column come from a set of discrete values or codes. For example, a person's sex may be Female, Male or Non-Binary. Foreign-key constraints: This is the more general case of set membership. The set of values in a column is defined in a column of another table that contains unique values.