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From Apache Wiki <wikidi...@apache.org>
Subject [Lucene-hadoop Wiki] Update of "Hbase/HbaseArchitecture" by JimKellerman
Date Sun, 18 Mar 2007 01:10:34 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 JimKellerman:
http://wiki.apache.org/lucene-hadoop/Hbase/HbaseArchitecture

The comment on the change is:
document how data is organized in a Hadoop MapFile

------------------------------------------------------------------------------
  the value for ''t6'' and the value for an ''"anchor"''  for
  "my.look.ca" if no time stamp is supplied is the value for time stamp
  ''t8''.
-  
+ 
+ === Example ===
+ 
+ The current unit test for HBase included in the patch on
+ [http://issues.apache.org/jira/browse/HADOOP-1045 Hadoop Jira Issue 1045], 
+ first writes rows with row id's of the form "row_[0-9]+" where the row
+ number goes from 0 to 999. It writes to two column families:
+ "contents:basic" and "anchor:anchornum-[0-9]+" (again the range of
+ numbers for the anchornum family goes from 0 to 999). It then writes
+ rows with row id's of "row_vals_nnn" where nnn is a three digit,
+ leading zero filled number from 000 to 999. Two column families are
+ written: "contents:firstcol" and anchor:secondcol". After a
+ compaction, dumping the
+ !MapFile which contains the "anchor:" family we see that the keys,
+ displayed as column-family(row-key)/timestamp are ordered as follows:
+ 
+ {{{
+ anchor:anchornum-0(row_0)/1174176403717
+ anchor:anchornum-1(row_1)/1174176403723
+ anchor:anchornum-10(row_10)/1174176403726
+ anchor:anchornum-100(row_100)/1174176403769
+ anchor:anchornum-101(row_101)/1174176403770
+ anchor:anchornum-102(row_102)/1174176403771
+ anchor:anchornum-103(row_103)/1174176403771
+ anchor:anchornum-104(row_104)/1174176403772
+ anchor:anchornum-105(row_105)/1174176403772
+ anchor:anchornum-106(row_106)/1174176403773
+ anchor:anchornum-107(row_107)/1174176403773
+ anchor:anchornum-108(row_108)/1174176403774
+ anchor:anchornum-109(row_109)/1174176403774
+ anchor:anchornum-11(row_11)/1174176403727
+ ...
+ anchor:anchornum-99(row_99)/1174176403769
+ anchor:anchornum-990(row_990)/1174176403966
+ anchor:anchornum-991(row_991)/1174176403966
+ anchor:anchornum-992(row_992)/1174176403966
+ anchor:anchornum-993(row_993)/1174176403966
+ anchor:anchornum-994(row_994)/1174176403966
+ anchor:anchornum-995(row_995)/1174176403966
+ anchor:anchornum-996(row_996)/1174176403966
+ anchor:anchornum-997(row_997)/1174176403966
+ anchor:anchornum-998(row_998)/1174176403966
+ anchor:anchornum-999(row_999)/1174176403966
+ anchor:secondcol(row_vals1_000)/1174176435765
+ anchor:secondcol(row_vals1_001)/1174176435766
+ anchor:secondcol(row_vals1_002)/1174176435767
+ anchor:secondcol(row_vals1_003)/1174176435767
+ anchor:secondcol(row_vals1_004)/1174176435767
+ anchor:secondcol(row_vals1_005)/1174176435767
+ anchor:secondcol(row_vals1_006)/1174176435768
+ anchor:secondcol(row_vals1_007)/1174176435768
+ anchor:secondcol(row_vals1_008)/1174176435769
+ anchor:secondcol(row_vals1_009)/1174176435769
+ anchor:secondcol(row_vals1_010)/1174176435770
+ ...
+ }}}
+ 
+ If the row keys had had the same format (say row_nnn), dumping the
+ !MapFile we would see:
+ 
+ {{{
+ anchor:anchornum-0(row_000)/1174176403717
+ anchor:secondcol(row_000)/1174176435765
+ anchor:anchornum-1(row_001)/1174176403723
+ anchor:secondcol(row_001)/1174176435766
+ ...
+ }}}
+ 
  [[Anchor(hregion)]]
  = HRegion (Tablet) Server =
  

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