hadoop-common-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Apache Wiki <wikidi...@apache.org>
Subject [Lucene-hadoop Wiki] Trivial Update of "Hbase/HbaseShell/ShellPlans" by udanax
Date Fri, 26 Oct 2007 07:18:15 GMT
Dear Wiki user,

You have subscribed to a wiki page or wiki category on "Lucene-hadoop Wiki" for change notification.

The following page has been changed by udanax:
http://wiki.apache.org/lucene-hadoop/Hbase/HbaseShell/ShellPlans

------------------------------------------------------------------------------
  
  == Hbase Shell Algebraic Commands ==
  
- Of course, I'll re-arrange tastefully the Language.
- 
  === Relational Algebra Operations ===
  
   * https://issues.apache.org/jira/browse/HADOOP-1608
-  * Projection 
+ ==== Projection ====
    * selects a subset of the columnfamilies of a relation
    * Result = π ,,column_list,, (Relation) 
  {{{
+ Relation
  +---------------------------------------------------+
  | title         year   length  inColor studioName   |
  | ================================================= |
@@ -25, +24 @@

  Hbase > Result = Relation.Projection('year','legnth');
  Hbase > save Result into table('result');
  
+ Result
  +------------------------------+
  | title         year   length  |
  | ============================ |
@@ -32, +32 @@

  | Mighty Ducks  1991   104     |
  +------------------------------+
  }}}
-  * Selection
+ ==== Selection ====
    * selects a subset of the rows in a relation that satisfy a selection condition
    * Result = σ ,,selection_condition,, (Relation) 
  {{{
+ Relation
  +---------------------------------------------------+
  | title         year   length  inColor studioName   |
  | ================================================= |
@@ -47, +48 @@

       or Result = Relation.Selection(length > 100 and studioName NOT IN ('Fox', 'Paramound'));
  Hbase > save Result into table('result');
  
+ Result
  +---------------------------------------------------+
  | title         year   length  inColor studioName   |
  | ================================================= |
@@ -54, +56 @@

  +---------------------------------------------------+
  }}}
  
-  * Group 
+ ==== Group ====
    * Aggregation functions on collections of data values: average, minimum, maximum, sum,
count.
    * Group rows by value of an columnfamily and apply aggregate function independently to
each group of rows.
    * <Grouping columnfamilies> ƒ ,,function_list,, (Relation) 
@@ -62, +64 @@

  Hbase > Group Relation by (studioName, SUM('vote:user'));
  }}}
  
-  * θ Join 
+ ==== θ Join ====
    * The join of two relations R1(A,,1,, ,A,,2,, ,...,A,,n,,) and R2(B,,1,, ,B,,2,, ,...,B,,m,,)
is a relation with degree k=n+m and attributes (A,,1,, ,A,,2,, ,...,A,,n,, , B,,1,, ,B,,2,,
,...,B,,m,,) that satisfy the join condition 
    * Result = R1 ▷◁ ,,θ join_condition,, R2
  {{{
@@ -92, +94 @@

  
  Result
  +-------------------------------------------------------------------------------------------------------------------+
- | title         producer      actor                            studioName         occupation
 birth       knownFor  |               
+ | title         producer      actor                            studioName         occupation
 birth       knownFor  |
  | =================================================================================================================
|
  | The Bodyguard Mick Jackson  actor:heroine <Whitney Houston>  Warner Home Video 
Singer      Aug 9, 1963 Diva      |
- +-------------------------------------------------------------------------------------------------------------------+
  
+ +-------------------------------------------------------------------------------------------------------------------+
  }}}
  
  === Linear Algebra Operations ===

Mime
View raw message