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From Apache Wiki <wikidi...@apache.org>
Subject [Lucene-hadoop Wiki] Trivial Update of "Hbase/HbaseShell/ShellPlans" by udanax
Date Thu, 11 Oct 2007 08:11:23 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 Plans =
+ = Relational Algebra Operators =
+ 
+  * https://issues.apache.org/jira/browse/HADOOP-1608
+  * Projection 
+   * selects a subset of the columnfamilies of a relation
+   * Result = π ,,column_list,, (Relation) 
+ {{{
+ Hbase > Result = Relation.Projection('year','legnth');
+ Hbase > save Result into table('result');
+ }}}
+  * Selection
+   * selects a subset of the rows in a relation that satisfy a selection condition
+   * Result = σ ,,selection_condition,, (Relation) 
+ {{{
+ Hbase > Result = Relation.Selection(length > 100 and studioName = 'Fox'); 
+      or Result = Relation.Selection(length > 100 and studioName NOT IN ('Fox', 'Paramound'));
+ Hbase > save Result into table('result');
+ }}}
+ 
+  * 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) 
+ {{{
+ Hbase > Group Relation by (studioName, SUM('vote:user'));
+ }}}
+ 
+  * 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
+ {{{
+ Hbase > R1 = table('movieLog_table');
+ Hbase > R2 = table('personInfo_table');
+ Hbase > Result = R1.join(R1.producer: = R2.ROW) and R2; 
+      or Result = R1.join(R1.actor:hero = R2.Row) and R2;
+ }}}
+ 
+ ----
  
  Isn't this query impossible?
  

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