Question

有人能告诉我，如何列出hbase表中的所有行键？

Answer 1

HBase shell可用于列出所有行键：

count 'table_name', { INTERVAL => 1 }

Answer 2

这应该快得多（FirstKeyOnlyFilter在服务器上运行并在将结果发送到客户端之前删除所有列数据）：

Configuration conf = HBaseConfiguration.create();
HTable table = new HTable(conf, tableName.getBytes());
System.out.println("scanning full table:");
Scan scan = new Scan();
scan.setFilter(new FirstKeyOnlyFilter());
ResultScanner scanner = table.getScanner(scan);
for (Result rr : scanner) {
  byte[] key == rr.getRow();
  ...
}

Answer 3

Configuration conf = HBaseConfiguration.create();
HTable table = new HTable(conf, tableName.getBytes());

System.out.println("scanning full table:");
ResultScanner scanner = table.getScanner(new Scan());
for (Result rr = scanner.next(); rr != null; rr = scanner.next()) {
  byte[] key == rr.getRow();
  ...
}

Answer 4

执行只需要行键的表扫描（无族，限定符，值或时间戳）时，使用setFilter将带有MUST_PASS_ALL运算符的FilterList添加到扫描程序。筛选器列表应包括FirstKeyOnlyFilter和KeyOnlyFilter。使用此过滤器组合将导致RegionServer从磁盘读取单个值的最坏情况和单个行到客户端的最小网络流量。

Answer 5

使用Result类的getRow方法。它的描述说：

检索与行对应的行键的方法该结果已创建。

假设table是您的hbase表并且您已连接到HBase实例，那么您需要做的就是：

Scan scan = new Scan();
ResultScanner rscanner = table.getScanner(scan);
for(Result r : rscanner){
   //r is the result object that contains the row
   //do something
   System.out.println(Bytes.toString(r.getRow())); //doing something
}

我知道这已经从Java API的角度来回答了，但更多的细节从未伤害过任何人。

Answer 6

似乎你想在PHP中使用HBase thrift客户端。下面是一个示例代码，您可以获取HBase中的所有数据并获取其行键。

<? $_SERVER['PHP_ROOT'] = realpath(dirname(__FILE__).'/..');
   require_once $_SERVER['PHP_ROOT'].'/flib/__flib.php';
   flib_init(FLIB_CONTEXT_SCRIPT);
   require_module('storage/hbase');
   $hbase = new HBase('<server_name_running_thrift_server>', <port on which thrift server is running>);
   $hbase->open();
   $client = $hbase->getClient();
   $result = $client->scannerOpenWithFilterString('table_name', "(PrefixFilter ('row2') AND (QualifierFilter (>=, 'binary:xyz'))) AND (TimestampsFilter ( 123, 456))");
   $to_print = $client->scannerGetList($result,1);
   while ($to_print) {
      print_r($to_print);
      $to_print = $client->scannerGetList($result,1);
    }
   $client->scannerClose($result);
?>

如何列出hbase表中的所有行键？

6 个答案: