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  2. Delete (SQL) - Wikipedia

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

    DELETE requires a shared table lock; Triggers fire; DELETE can be used in the case of: database link; DELETE returns the number of records deleted; Transaction log - DELETE needs to read records, check constraints, update block, update indexes, and generate redo / undo. All of this takes time, hence it takes time much longer than with TRUNCATE

  3. Data orientation - Wikipedia

    en.wikipedia.org/wiki/Data_orientation

    The two most common representations are column-oriented (columnar format) and row-oriented (row format). [ 1 ] [ 2 ] The choice of data orientation is a trade-off and an architectural decision in databases , query engines, and numerical simulations. [ 1 ]

  4. Truncate (SQL) - Wikipedia

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

    In SQL, the TRUNCATE TABLE statement is a data manipulation language (DML) [1] operation that deletes all rows of a table without causing a triggered action. The result of this operation quickly removes all data from a table, typically bypassing a number of integrity enforcing mechanisms.

  5. Data manipulation language - Wikipedia

    en.wikipedia.org/wiki/Data_manipulation_language

    In SQL, the data manipulation language comprises the SQL-data change statements, [3] which modify stored data but not the schema or database objects. Manipulation of persistent database objects, e.g., tables or stored procedures, via the SQL schema statements, [3] rather than the data stored within them, is considered to be part of a separate data definition language (DDL).

  6. Referential integrity - Wikipedia

    en.wikipedia.org/wiki/Referential_integrity

    Also, self-references are possible (not fully implemented in MS SQL Server though [5]). On inserting a new row into the referencing table, the relational database management system (RDBMS) checks if the entered key value exists in the referenced table. If not, no insert is possible.

  7. Select (SQL) - Wikipedia

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

    SELECT * FROM (SELECT ROW_NUMBER OVER (ORDER BY sort_key ASC) AS row_number, columns FROM tablename) AS foo WHERE row_number <= 10 ROW_NUMBER can be non-deterministic : if sort_key is not unique, each time you run the query it is possible to get different row numbers assigned to any rows where sort_key is the same.

  8. Template:Currency - Wikipedia

    en.wikipedia.org/wiki/Template:Currency

    When set to any value, produces a long-form currency name. This should be used for the first mention of a currency within the article. Line: optional: Link currency: linked: Whether to link to the article on that currency. “no” suppresses the link, any other value displays it. Default yes Example no: Line: optional: Format: fmt

  9. Decimalisation - Wikipedia

    en.wikipedia.org/wiki/Decimalisation

    Decimalisation or decimalization (see spelling differences) is the conversion of a system of currency or of weights and measures to units related by powers of 10.. Most countries have decimalised their currencies, converting them from non-decimal sub-units to a decimal system, with one basic currency unit and sub-units that are valued relative to the basic unit by a power of 10, most commonly ...