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The following page has been changed by udanax: http://wiki.apache.org/lucene-hadoop/Hbase/HbaseShell ------------------------------------------------------------------------------ ||Delete ||'''Delete''' command deletes specified rows in table. [[BR]][[BR]]~-''DELETE { column_name, [, column_name] ... | COLUMNFAMILIES(column_family[, column_family] ... | *} [[BR]]{{{ }}}FROM table_name[[BR]]{{{ }}}[WHERE row = 'row-key'];''-~ || ||Select ||<99%>'''Select''' command retrieves rows from a table.[[BR]][[BR]]~-''SELECT { column_name [, column_name] ... | * }[[BR]]{{{ }}}FROM table_name[[BR]]{{{ }}}[WHERE row = 'row-key' | STARTING FROM 'row-key'][[BR]]{{{ }}}[NUM_VERSIONS = version_count][[BR]]{{{ }}}[TIMESTAMP 'timestamp'][[BR]]{{{ }}}[LIMIT = row_count][[BR]]{{{ }}}[INTO FILE 'file_name'][[BR]][[BR]]''-~'''column_name:'''~-''[[BR]]{{{ }}}column_family_name[[BR]]{{{ }}}| column_family_name:column_label_name''-~ || - - == Algebraic Query Commands == - - ||<bgcolor="#E5E5E5">'''Command''' ||<bgcolor="#E5E5E5">'''Explanation''' || - ||Table ||<99%>'''Table''' command loads specified table. [[BR]][[BR]]~-''Table('table_name');''-~ || - ||Substitute ||<99%>'''Substitute''' specific algebraic expression to specified string[[BR]][[BR]]~-''A = Projection(column-list);''-~ || - ||Save ||<99%>'''Save''' command will save results to specified table or matrix. [[BR]][[BR]]~-''A = Table('table_name'); [[BR]]B = A.Selection(condition_expression); [[BR]]Save B Into table(result_table);''-~ || - - === Relational Algebra Operators === - - ||<bgcolor="#E5E5E5">'''Operator''' ||<bgcolor="#E5E5E5">'''Explanation''' || - ||Projection ||<99%>'''Projection''' of a relation ~+R+~, It makes a new relation as the set that is obtained when all rows in ~+R+~ are restricted to the set {columnfamily,,1,,,...,columnfamily,,n,,}.[[BR]][[BR]]~-''A = Table('table_name');[[BR]]B = A.Projection(column-list);''-~ || - ||Selection ||<99%>'''Selection''' of a relation ~+R+~, It makes a new relation as the set of specified rows of the relation ~+R+~.[[BR]]'''Set Operations''' : ~-''OR, AND, NOT''-~[[BR]][[BR]]~-''A = Table('table_name');[[BR]]B = A.Selection(condition_expression);''-~ || - ||JOIN ||<99%>Table '''JOIN''' operations, linking and extracting data from two different internal source.[[BR]][[BR]]~-''R = Table('table_name1');[[BR]]S = Table('table_name2');[[BR]]C = R.Join(condition_expression) and S;''-~ || - ||Group ||<99%>'''Group''' tuples by value of an attribute and apply aggregate function independently to each group of tuples.[[BR]]'''Aggregate Functions''' : ~-''AVG(attribute), SUM(attribute), COUNT(attribute), MIN(attribute), MAX(attribute)''-~[[BR]][[BR]]~-''A = Table('table_name');[[BR]]B = A.Group(column-list);''-~ || -
