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] Update of "Hbase/HbaseShell" by udanax
Date Sat, 29 Dec 2007 09:07:54 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

------------------------------------------------------------------------------
  ||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);''-~ ||
- 

Mime
View raw message