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From Apache Wiki <wikidi...@apache.org>
Subject [Db-derby Wiki] Update of "OLAPOperations" by BryanPendleton
Date Fri, 20 Jul 2007 21:34:13 GMT
Dear Wiki user,

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The following page has been changed by BryanPendleton:
http://wiki.apache.org/db-derby/OLAPOperations

------------------------------------------------------------------------------
   * T431: Extended grouping capabilities
   * T433: Multiargument GROUPING function
  
- This page, which is currently a stub, is intended to contain information about OLAP operations
and Derby.
+ This page, and the other pages to which it links, are intended to contain information about
OLAP operations and Derby.
  
  == T611: Elementary OLAP operations ==
  
  Feature T611 of the 2003 SQL standard specifies the following items:
-  * Window functions (ROW_NUMBER, RANK, and DENSE_RANK)
+  * Window functions ([:OLAPRowNumber:ROW_NUMBER], RANK, and DENSE_RANK)
   * Unnamed window specifications:
     * window partitioning (PARTITION BY)
     * window ordering (ORDER BY)
@@ -53, +53 @@

  
  == Windows and Window Functions ==
  
+ === Windowed Table ===
+ 
+ A '''windowed table''' is a table together with one or more windows.
+ 
  === Window ===
  
  A '''window''' is a subset of the rows in the result set of the query to which a window
function should be applied. A window describes how to partition the rows of the result set
into one or more partitions, how to order the rows within each partition, and which particular
rows to include within that window.
@@ -64, +68 @@

      ORDER BY date_of_sale
      ROWS UNBOUNDED PRECEDING)
  }}}
+ 
+ Every window defines a partitioning of the rows of the <table expression>. Window
partitioning is similar to forming groups of a grouped table. However, unlike grouped tables,
each row is retained in the transient window data structure. The window partition of a row
R is the multi-set of rows that are not distinct from R for all columns in the PARTITION BY
clause (if the PARTITION BY clause is missing, the window contains all the rows in the result).
  
  === Window Function ===
  

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