doc-exports/docs/mrs/component-operation-guide-lts/mrs_01_0493.html

<a name="mrs_01_0493"></a><a name="mrs_01_0493"></a>

<h1 class="topictitle1">Supporting Full-Text Index</h1>
<div id="body8662426"><p id="mrs_01_0493__en-us_topic_0000001173789474_p731817329127">You can create tables and indexes using <strong id="mrs_01_0493__en-us_topic_0000001173789474_b167911229141410">createTable</strong> of <strong id="mrs_01_0493__en-us_topic_0000001173789474_b179120295142">org.apache.luna.client.LunaAdmin</strong> and specify table names, column family names, requests for creating indexes, as well as the directory path for storing mapping files. You can also add indexes to existing tables using <strong id="mrs_01_0493__en-us_topic_0000001173789474_b1866144181416">addCollection</strong> and obtain tables to perform a scan operation by using <strong id="mrs_01_0493__en-us_topic_0000001173789474_b16194552111417">getTable</strong> of <strong id="mrs_01_0493__en-us_topic_0000001173789474_b1319975214144">org.apache.luna.client.LunaAdmin</strong>.</p>
<p id="mrs_01_0493__en-us_topic_0000001173789474_p1973634161315">The column name and column family name of a table consist of letters, digits, and underscores (_) but cannot contain any special characters.</p>
<p id="mrs_01_0493__en-us_topic_0000001173789474_p13736154191316">HBase tables with a full-text index have the following limitations:</p>
<ul id="mrs_01_0493__en-us_topic_0000001173789474_ul252381021319"><li id="mrs_01_0493__en-us_topic_0000001173789474_li17460123121313">Disaster recovery, backup, and restoration are not supported.</li><li id="mrs_01_0493__en-us_topic_0000001173789474_li9421172816133">Rows and column families cannot be deleted.</li><li id="mrs_01_0493__en-us_topic_0000001173789474_li16219314451">Tight consistency is not supported by the query on Solr.</li></ul>
<div class="section" id="mrs_01_0493__en-us_topic_0000001173789474_section10642125451317"><h4 class="sectiontitle">Code Snippet Example</h4><p id="mrs_01_0493__en-us_topic_0000001173789474_p433710218148">The following code snippet belongs to the <strong id="mrs_01_0493__en-us_topic_0000001173789474_b0766191919159">testFullTextScan</strong> method in the <strong id="mrs_01_0493__en-us_topic_0000001173789474_b1077114195151">LunaSample</strong> class of the <strong id="mrs_01_0493__en-us_topic_0000001173789474_b7771101991517">hbase.examples</strong> package.</p>
<pre class="screen" id="mrs_01_0493__en-us_topic_0000001173789474_screen141207422188"> public static void testFullTextScan() throws Exception {
    /**
     * Create create request of Solr. Specify collection name, confset name,
     * number of shards, and number of replication factor.
     */
    Create create = new Create();
    create.setCollectionName(COLLECTION_NAME);
    create.setConfigName(CONFSET_NAME);
    create.setNumShards(NUM_OF_SHARDS);
    create.setReplicationFactor(NUM_OF_REPLICATIONFACTOR);
    /**
     * Create mapping. Specify index fields(mandatory) and non-index
     * fields(optional).
     */
    List&lt;ColumnField&gt; indexedFields = new ArrayList&lt;ColumnField&gt;();
    indexedFields.add(new ColumnField("name", "f:n"));
    indexedFields.add(new ColumnField("cat", "f:t"));
    indexedFields.add(new ColumnField("features", "f:d"));
    Mapping mapping = new Mapping(indexedFields);
    /**
     * Create table descriptor of HBase.
     */
    HTableDescriptor desc = new HTableDescriptor(HBASE_TABLE);
    desc.addFamily(new HColumnDescriptor(TABLE_FAMILY));
    /**
     * Create table and collection at the same time.
     */
    LunaAdmin admin = null;
    try {
      admin = new AdminSingleton().getAdmin();
      admin.deleteTable(HBASE_TABLE);
      if (!admin.tableExists(HBASE_TABLE)) {
        admin.createTable(desc, Bytes.toByteArrays(new String[] { "0", "1", "2", "3", "4" }),
            create, mapping);
      }
      /**
       * Put data.
       */
      Table table = admin.getTable(HBASE_TABLE);
      int i = 0;
      while (i &lt; 5) {
        byte[] row = Bytes.toBytes(i + "+sohrowkey");
        Put put = new Put(row);
        put.addColumn(TABLE_FAMILY, Bytes.toBytes("n"), Bytes.toBytes("ZhangSan" + i));
        put.addColumn(TABLE_FAMILY, Bytes.toBytes("t"), Bytes.toBytes("CO" + i));
        put.addColumn(TABLE_FAMILY, Bytes.toBytes("d"), Bytes.toBytes("Male, Leader of M.O" + i));
        table.put(put);
        i++;
      }

      /**
       * Scan table.
       */
      Scan scan = new Scan();
      SolrQuery query = new SolrQuery();
      query.setQuery("name:ZhangSan1 AND cat:CO1");
      Filter filter = new FullTextFilter(query, COLLECTION_NAME);
      scan.setFilter(filter);
      ResultScanner scanner = table.getScanner(scan);
      LOG.info("-----------------records----------------");
      for (Result r = scanner.next(); r != null; r = scanner.next()) {
        for (Cell cell : r.rawCells()) {
          LOG.info(Bytes.toString(CellUtil.cloneRow(cell)) + ":"
              + Bytes.toString(CellUtil.cloneFamily(cell)) + ","
              + Bytes.toString(CellUtil.cloneQualifier(cell)) + ","
              + Bytes.toString(CellUtil.cloneValue(cell)));
        }
      }
      LOG.info("-------------------end------------------");
      /**
       * Delete collection.
       */
      admin.deleteCollection(HBASE_TABLE, COLLECTION_NAME);

      /**
       * Delete table.
       */
      admin.deleteTable(HBASE_TABLE);
    } catch (IOException e) {
      e.printStackTrace();
    } finally {
      /**
       * When everything done, close LunaAdmin.
       */
      admin.close();
    }
  }</pre>
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<div class="section" id="mrs_01_0493__en-us_topic_0000001173789474_section4845633112312"><h4 class="sectiontitle">Precautions</h4><ul id="mrs_01_0493__en-us_topic_0000001173789474_ul1825538182311"><li id="mrs_01_0493__en-us_topic_0000001173789474_li72523852312">Tables and indexes to be created must be unique.</li><li id="mrs_01_0493__en-us_topic_0000001173789474_li17251384236">Use LunaAdmin only to obtain tables to perform a scan operation.</li></ul>
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<div class="familylinks">
<div class="parentlink"><strong>Parent topic:</strong> <a href="mrs_01_0500.html">Using HBase</a></div>
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