svn commit: r1181307 - /hbase/trunk/src/docbkx/book.xml

[dm...@apache.org]

Author: dmeil
Date: Tue Oct 11 00:15:52 2011
New Revision: 1181307

URL: http://svn.apache.org/viewvc?rev=1181307&view=rev
Log:
HBASE-4571.  book.xml, adding Schema Design Smackdown section.

Modified:
    hbase/trunk/src/docbkx/book.xml

Modified: hbase/trunk/src/docbkx/book.xml
URL: http://svn.apache.org/viewvc/hbase/trunk/src/docbkx/book.xml?rev=1181307&r1=1181306&r2=1181307&view=diff
==============================================================================
--- hbase/trunk/src/docbkx/book.xml (original)
+++ hbase/trunk/src/docbkx/book.xml Tue Oct 11 00:15:52 2011
@@ -593,6 +593,27 @@ admin.enableTable(table);               
       </para>
     </section>
   </section>
+  <section xml:id="schema.smackdown"><title>Schema Design Smackdown</title>
+    <para>This section will describe common schema design questions that appear on the dist-list.  These are 
+    general guidelines and not laws - each application must consider it's own needs.  
+    </para>
+    <section xml:id="schema.smackdown.rowsversions"><title>Rows vs. Versions</title>
+      <para>A common question is whether one should prefer rows or HBase's built-in-versioning.  The context is typically where there are
+      "a lot" of versions of a row to be retained (e.g., where it is significantly above the HBase default of 3 max versions).  The 
+      rows-approach would require storing a timstamp in some portion of the rowkey so that they would not overwite with each successive update.
+      </para>
+      <para>Winner:  Rows (generally speaking).
+      </para>
+    </section>
+    <section xml:id="schema.smackdown.rowscols"><title>Rows vs. Columns</title>
+      <para>Another common question is whether one should prefer rows or columns.  The context is typically in extreme cases of wide
+      tables, such as having 1 row with 1 million attributes, or 1 million rows with 1 columns apiece.  
+      </para>
+      <para>Winner:  Rows (generally speaking).  To be clear, this guideline is in the context is in extremely wide cases, not where 
+      one needs to store a few dozen or hundred columns.
+      </para>
+    </section>
+  </section>
 
   </chapter>