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HBASE-9004 Fix Documentation around Minor Compaction and TTL (Masatake Iwasaki)

This commit is contained in:
Misty Stanley-Jones 2014-10-07 13:32:51 +10:00
parent 0209e1c760
commit f80d4ba16f
1 changed files with 14 additions and 9 deletions
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23
src/main/docbkx/schema_design.xml
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@ -368,10 +368,10 @@ COLUMN CELL
<para>If you pre-split your table, it is <emphasis>critical</emphasis> to understand how your
rowkey will be distributed across the region boundaries. As an example of why this is
important, consider the example of using displayable hex characters as the lead position of
the key (e.g., &quot;0000000000000000&quot; to &quot;ffffffffffffffff&quot;). Running those
key ranges through <code>Bytes.split</code> (which is the split strategy used when creating
regions in <code>HBaseAdmin.createTable(byte[] startKey, byte[] endKey, numRegions)</code>
for 10 regions will generate the following splits... </para>
the key (e.g., "0000000000000000" to "ffffffffffffffff"). Running those key ranges through
<code>Bytes.split</code> (which is the split strategy used when creating regions in
<code>HBaseAdmin.createTable(byte[] startKey, byte[] endKey, numRegions)</code> for 10
regions will generate the following splits...</para>
<screen>
48 48 48 48 48 48 48 48 48 48 48 48 48 48 48 48 // 0
54 -10 -10 -10 -10 -10 -10 -10 -10 -10 -10 -10 -10 -10 -10 -10 // 6
@ -498,12 +498,17 @@ public static byte[][] getHexSplits(String startKey, String endKey, int numRegio
<section
xml:id="ttl">
<title>Time To Live (TTL)</title>
<para>ColumnFamilies can set a TTL length in seconds, and HBase will automatically delete rows
<para> ColumnFamilies can set a TTL length in seconds, and HBase will automatically delete rows
once the expiration time is reached. This applies to <emphasis>all</emphasis> versions of a
row - even the current one. The TTL time encoded in the HBase for the row is specified in UTC. </para>
<para>See <link
xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/HColumnDescriptor.html">HColumnDescriptor</link>
for more information. </para>
row - even the current one. The TTL time encoded in the HBase for the row is specified in UTC.
</para>
<para> Store files which contains only expired rows are deleted on minor compaction. Setting
<varname>hbase.store.delete.expired.storefile</varname> to <code>false</code> disables this
feature. Setting <link linkend="schema.minversions">minimum number of versions</link> to other
than 0 also disables this.</para>
<para> See <link
xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/HColumnDescriptor.html"
>HColumnDescriptor</link> for more information. </para>
</section>
<section
xml:id="cf.keep.deleted">