When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Database trigger - Wikipedia

    en.wikipedia.org/wiki/Database_trigger

    Suppose you have a trigger that is called on an INSERT to a certain table. If your trigger is using the BEFORE option, the code within the trigger will be executed before the INSERT into the table occurs. A common use of the BEFORE trigger is to verify the input values of the INSERT, or modify the values accordingly.

  3. Virtual column - Wikipedia

    en.wikipedia.org/wiki/Virtual_column

    In relational databases a virtual column is a table column whose value(s) is automatically computed using other columns values, or another deterministic expression. Virtual columns are defined of SQL:2003 as Generated Column, [1] and are only implemented by some DBMSs, like MariaDB, SQL Server, Oracle, PostgreSQL, SQLite and Firebird (database server) (COMPUTED BY syntax).

  4. List of SQL reserved words - Wikipedia

    en.wikipedia.org/wiki/List_of_SQL_reserved_words

    Reserved words in SQL and related products In SQL:2023 [3] In IBM Db2 13 [4] In Mimer SQL 11.0 [5] In MySQL 8.0 [6] In Oracle Database 23c [7] In PostgreSQL 16 [1] In Microsoft SQL Server 2022 [2]

  5. Oracle Data Guard - Wikipedia

    en.wikipedia.org/wiki/Oracle_Data_Guard

    Oracle provides both graphical user interface (GUI) and command-line (CLI) tools for managing Data Guard configurations. Data Guard supports both physical standby and logical standby sites. Oracle Corporation makes Data Guard available only as a bundled feature included within its "Enterprise Edition" of the Oracle RDBMS .

  6. Sequence number - Wikipedia

    en.wikipedia.org/wiki/Sequence_number

    A sequence number is a consecutive number in a sequence of numbers, usually of real integers (natural numbers).Sequence numbers have many practical applications. They can be used, among other things, as part of serial numbers on manufactured parts, in case management, [1] or in databases as a surrogate key for registering and identifying unique entries in a table [2] [3] (in which case it is ...

  7. Skip list - Wikipedia

    en.wikipedia.org/wiki/Skip_list

    A schematic picture of the skip list data structure. Each box with an arrow represents a pointer and a row is a linked list giving a sparse subsequence; the numbered boxes (in yellow) at the bottom represent the ordered data sequence. Searching proceeds downwards from the sparsest subsequence at the top until consecutive elements bracketing the ...

  8. Insertion sort - Wikipedia

    en.wikipedia.org/wiki/Insertion_sort

    The function has the side effect of overwriting the value stored immediately after the sorted sequence in the array. To perform an insertion sort, begin at the left-most element of the array and invoke Insert to insert each element encountered into its correct position. The ordered sequence into which the element is inserted is stored at the ...

  9. Sequence diagram - Wikipedia

    en.wikipedia.org/wiki/Sequence_diagram

    A system sequence diagram should be done for the main success scenario of the use case, and frequent or complex alternative scenarios. There are two kinds of sequence diagrams: Sequence Diagram (SD): A regular version of sequence diagram describes how the system operates, and every object within a system is described specifically.