hbase数据条数如何准确统计

HBase???????????????????,??????????

1. ??count()??:

?HBase Shell?,?????count()???????????????????????????,?????????,??????????

hbase(main):001:0> count 'your_table_name'

2. ??Scan?Count:

??????Java API?????????,??Scan???Count????????????????????:

import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.*;

public class HBaseCountRows {
    public static void main(String[] args) throws Exception {
        Configuration conf = HBaseConfiguration.create();
        Connection connection = ConnectionFactory.createConnection(conf);
        Admin admin = connection.getAdmin();

        TableName tableName = TableName.valueOf("your_table_name");
        Scan scan = new Scan();
        scan.setCountOnly(true);

        ResultScanner scanner = admin.getScanner(tableName, scan);
        int rowCount = 0;
        for (Result result : scanner) {
            rowCount++;
        }

        System.out.println("Total rows: " + rowCount);

        scanner.close();
        admin.close();
        connection.close();
    }
}

3. ??Count?Get:

????????Count?Get????????????????????????????,??????????????????????:

import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.*;

public class HBaseCountRows {
    public static void main(String[] args) throws Exception {
        Configuration conf = HBaseConfiguration.create();
        Connection connection = ConnectionFactory.createConnection(conf);
        Admin admin = connection.getAdmin();

        TableName tableName = TableName.valueOf("your_table_name");

        int rowCount = 0;
        for (int i = 0; i < 100; i++) { // Assuming the table is large enough to require multiple Get requests
            Get get = new Get(Bytes.toBytes(String.format("d", i)));
            Result result = admin.get(tableName, get);
            if (result.isEmpty()) {
                break; // No more data
            }
            rowCount++;
        }

        System.out.println("Total rows: " + rowCount);

        admin.close();
        connection.close();
    }
}

???,?????????HBase????????????????????,????count()???Java API??Scan?????????????