Apache
/
hbase
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

HBASE-4600 book.xml 

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1184932 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Doug Meil 2011-10-16 21:03:25 +00:00
parent 1f44a8ce1e
commit c89957e92a
1 changed files with 18 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

33
src/docbkx/book.xml
View File

@ -421,7 +421,8 @@ put.add(Bytes.toBytes("cf"), Bytes.toBytes("attr1"), explicitTimeInMs, Bytes.toB
htable.put(put);
</programlisting>
Caution: the version timestamp is internally by HBase for things like time-to-live calculations.
It's usually best to avoid setting the timestamp yourself.
It's usually best to avoid setting this timestamp yourself. Prefer using a separate
timestamp attribute of the row, or have the timestamp a part of the rowkey, or both.
</para>
</section>
@ -1614,25 +1615,27 @@ scan.setFilter(filter);
<para>Even though these are for the same row, a KeyValue is created for each column:</para>
<para>Key portion for Put #1:
<itemizedlist>
<listitem>rowlength (4)</listitem>
<listitem>row (row1)</listitem>
<listitem>columnfamilylength (2)</listitem>
<listitem>columnfamily (cf)</listitem>
<listitem>columnqualifier (attr1)</listitem>
<listitem>timestamp (server time of Put)</listitem>
<listitem>keytype (Put)</listitem>
<listitem>rowlength <code>------------&gt; 4</code></listitem>
<listitem>row <code>-----------------&gt; row1</code></listitem>
<listitem>columnfamilylength <code>---&gt; 2</code></listitem>
<listitem>columnfamily <code>--------&gt; cf</code></listitem>
<listitem>columnqualifier <code>------&gt; attr1</code></listitem>
<listitem>timestamp <code>-----------&gt; server time of Put</code></listitem>
<listitem>keytype <code>-------------&gt; Put</code></listitem>
</itemizedlist>
</para>
<para>Key portion for Put #2:
<itemizedlist>
<listitem>rowlength (4)</listitem>
<listitem>row (row1)</listitem>
<listitem>columnfamilylength (2)</listitem>
<listitem>columnfamily (cf)</listitem>
<listitem>columnqualifier (attr2)</listitem>
<listitem>timestamp (server time of Put)</listitem>
<listitem>keytype (Put)</listitem>
<listitem>rowlength <code>------------&gt; 4</code></listitem>
<listitem>row <code>-----------------&gt; row1</code></listitem>
<listitem>columnfamilylength <code>---&gt; 2</code></listitem>
<listitem>columnfamily <code>--------&gt; cf</code></listitem>
<listitem>columnqualifier <code>------&gt; attr2</code></listitem>
<listitem>timestamp <code>-----------&gt; server time of Put</code></listitem>
<listitem>keytype <code>-------------&gt; Put</code></listitem>
</itemizedlist>
<!-- trying to get the above arrows to line up at the same horizontal position has proven
harder than I thought -->
</para>
</section>
<para>It is critical to understand that the rowkey, ColumnFamily, and column (aka columnqualifier) are embedded within