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