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  2. Table (database) - Wikipedia

    en.wikipedia.org/wiki/Table_(database)

    A specific choice of columns which uniquely identify rows is called the primary key. "Table" is another term for "relation"; although there is the difference in that a table is usually a multiset (bag) of rows where a relation is a set and does not allow duplicates. Besides the actual data rows, tables generally have associated with them some ...

  3. Help:Introduction to tables with Wiki Markup/All - Wikipedia

    en.wikipedia.org/wiki/Help:Introduction_to...

    Tables are a common way of displaying data. This tutorial provides a guide to making new tables and editing existing ones. For guidelines on when and how to use tables, see the Manual of Style. The easiest way to insert a new table is to use the editing toolbar that appears when you edit a page (see image above).

  4. pandas (software) - Wikipedia

    en.wikipedia.org/wiki/Pandas_(software)

    Pandas (styled as pandas) is a software library written for the Python programming language for data manipulation and analysis. In particular, it offers data structures and operations for manipulating numerical tables and time series .

  5. Relation (database) - Wikipedia

    en.wikipedia.org/wiki/Relation_(database)

    Relation, tuple, and attribute represented as table, row, and column respectively. In database theory, a relation, as originally defined by E. F. Codd, [1] is a set of tuples (d 1,d 2,...,d n), where each element d j is a member of D j, a data domain. Codd's original definition notwithstanding, and contrary to the usual definition in ...

  6. Database index - Wikipedia

    en.wikipedia.org/wiki/Database_index

    The data rows may be spread throughout the table regardless of the value of the indexed column or expression. The non-clustered index tree contains the index keys in sorted order, with the leaf level of the index containing the pointer to the record (page and the row number in the data page in page-organized engines; row offset in file ...

  7. Column (database) - Wikipedia

    en.wikipedia.org/wiki/Column_(database)

    However, database perfectionists tend to favor using 'field' to signify a specific cell of a given row. [citation needed] This is to enable accuracy in communicating with other developers. Columns (really column names) being referred to as field names (common for each row/record in the table).

  8. Entity–attribute–value model - Wikipedia

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

    This data representation is analogous to space-efficient methods of storing a sparse matrix, where only non-empty values are stored.In an EAV data model, each attribute–value pair is a fact describing an entity, and a row in an EAV table stores a single fact.

  9. Iterative proportional fitting - Wikipedia

    en.wikipedia.org/wiki/Iterative_proportional_fitting

    The iterative proportional fitting procedure (IPF or IPFP, also known as biproportional fitting or biproportion in statistics or economics (input-output analysis, etc.), RAS algorithm [1] in economics, raking in survey statistics, and matrix scaling in computer science) is the operation of finding the fitted matrix which is the closest to an initial matrix but with the row and column totals of ...