C++与Hive、Spark、libhdfs、ACID交互技巧-EW帮帮网

C++与Hive交互的实例

以下是C++与Hive交互的实例代码片段，涵盖连接、查询、数据操作等常见场景。假设使用libhdfs或thrift接口实现，部分示例需要结合Hive环境配置。

基础连接与查询

示例1：通过Thrift连接HiveServer2

#include <transport/TSocket.h>
#include <protocol/TBinaryProtocol.h>
#include <service/HiveClient.h>

using namespace apache::thrift;
using namespace apache::hive::service;

std::shared_ptr<TTransport> socket(new TSocket("localhost", 10000));
std::shared_ptr<TTransport> transport(new TBufferedTransport(socket));
std::shared_ptr<TProtocol> protocol(new TBinaryProtocol(transport));
HiveClient client(protocol);

transport->open();
client.execute("SHOW DATABASES");
transport->close();

示例2：执行简单查询并获取结果

std::vector<std::string> results;
client.fetchAll(results); // 假设已实现结果集遍历
for (const auto& row : results) {
    std::cout << row << std::endl;
}

数据操作

示例3：创建表

client.execute("CREATE TABLE users (id INT, name STRING)");

示例4：插入数据

client.execute("INSERT INTO users VALUES (1, 'Alice'), (2, 'Bob')");

示例5：批量插入（通过文件加载）

client.execute("LOAD DATA LOCAL INPATH '/path/to/data.csv' INTO TABLE users");

示例6：更新数据（需Hive支持ACID）

client.execute("UPDATE users SET name='Charlie' WHERE id=2");

示例7：删除数据

client.execute("DELETE FROM users WHERE id=1");

查询操作

示例8：条件查询

client.execute("SELECT * FROM users WHERE id > 1");

示例9：聚合查询

client.execute("SELECT COUNT(*), AVG(age) FROM employee");

示例10：JOIN操作

client.execute("SELECT a.*, b.department FROM employees a JOIN dept b ON a.dept_id = b.id");

示例11：子查询

client.execute("SELECT * FROM (SELECT id, name FROM users) tmp WHERE id < 100");

示例12：分区查询

client.execute("SELECT * FROM logs WHERE dt='2023-10-01'");

表操作

示例13：查看表结构

client.execute("DESCRIBE FORMATTED users");

示例14：添加列

client.execute("ALTER TABLE users ADD COLUMNS (age INT)");

示例15：重命名表

client.execute("ALTER TABLE users RENAME TO customers");

示例16：删除表

client.execute("DROP TABLE IF EXISTS users");

高级功能

示例17：使用UDF

client.execute("CREATE TEMPORARY FUNCTION my_udf AS 'com.example.MyUDF'");
client.execute("SELECT my_udf(name) FROM users");

示例18：窗口函数

client.execute("SELECT name, salary, RANK() OVER (PARTITION BY dept ORDER BY salary DESC) FROM employees");

示例19：动态分区插入

client.execute("SET hive.exec.dynamic.partition.mode=nonstrict");
client.execute("INSERT INTO TABLE logs PARTITION(dt) SELECT id, content, dt FROM source");

示例20：事务操作（Hive 3+）

client.execute("START TRANSACTION");
client.execute("INSERT INTO t1 VALUES (1)");
client.execute("COMMIT");

性能优化

示例21：设置并行度

client.execute("SET mapreduce.job.reduces=10");

示例22：使用Tez引擎

client.execute("SET hive.execution.engine=tez");

示例23：启用压缩

client.execute("SET hive.exec.compress.output=true");

示例24：使用桶表查询

client.execute("SELECT * FROM bucketed_users TABLESAMPLE(BUCKET 1 OUT OF 4)");

示例25：EXPLAIN分析

client.execute("EXPLAIN SELECT * FROM users WHERE id > 100");

注意事项

需确保HiveServer2服务已启动
部分功能依赖Hive版本（如ACID需Hive 3+）
实际开发中建议使用连接池管理Thrift连接
错误处理代码未完整展示，需自行添加异常捕获

使用C++实现ACID特性与Hive 3+交互的实例

以下是通过C++与Hive 3+交互实现ACID特性的实例，涵盖事务操作、数据一致性及性能优化。

连接Hive并创建ACID表

#include <sql.h>
#include <sqlext.h>
#include <iostream>

void createAcidTable() {
    SQLHENV env;
    SQLHDBC dbc;
    SQLHSTMT stmt;
    SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &env);
    SQLSetEnvAttr(env, SQL_ATTR_ODBC_VERSION, (void*)SQL_OV_ODBC3, 0);
    SQLAllocHandle(SQL_HANDLE_DBC, env, &dbc);
    SQLDriverConnect(dbc, NULL, (SQLCHAR*)"DSN=HiveDSN;", SQL_NTS, NULL, 0, NULL, SQL_DRIVER_COMPLETE);
    SQLAllocHandle(SQL_HANDLE_STMT, dbc, &stmt);
    SQLExecDirect(stmt, (SQLCHAR*)"CREATE TABLE acid_table (id INT, name STRING) STORED AS ORC TBLPROPERTIES ('transactional'='true')", SQL_NTS);
    SQLFreeHandle(SQL_HANDLE_STMT, stmt);
    SQLDisconnect(dbc);
    SQLFreeHandle(SQL_HANDLE_DBC, dbc);
    SQLFreeHandle(SQL_HANDLE_ENV, env);
}

开启事务并插入数据

void transactionalInsert() {
    SQLHSTMT stmt;
    SQLExecDirect(stmt, (SQLCHAR*)"START TRANSACTION", SQL_NTS);
    SQLExecDirect(stmt, (SQLCHAR*)"INSERT INTO acid_table VALUES (1, 'Alice')", SQL_NTS);
    SQLExecDirect(stmt, (SQLCHAR*)"COMMIT", SQL_NTS);
}

原子性操作示例

void atomicOperation() {
    try {
        SQLExecDirect(stmt, (SQLCHAR*)"START TRANSACTION", SQL_NTS);
        SQLExecDirect(stmt, (SQLCHAR*)"INSERT INTO acid_table VALUES (2, 'Bob')", SQL_NTS);
        throw std::runtime_error("Simulated failure");
        SQLExecDirect(stmt, (SQLCHAR*)"COMMIT", SQL_NTS);
    } catch (...) {
        SQLExecDirect(stmt, (SQLCHAR*)"ROLLBACK", SQL_NTS);
    }
}

批量插入优化

void batchInsert() {
    SQLExecDirect(stmt, (SQLCHAR*)"START TRANSACTION", SQL_NTS);
    for (int i = 0; i < 1000; ++i) {
        std::string query = "INSERT INTO acid_table VALUES (" + std::to_string(i) + ", 'User" + std::to_string(i) + "')";
        SQLExecDirect(stmt, (SQLCHAR*)query.c_str(), SQL_NTS);
    }
    SQLExecDirect(stmt, (SQLCHAR*)"COMMIT", SQL_NTS);
}

使用预编译语句

void preparedStatement() {
    SQLHSTMT stmt;
    SQLPrepare(stmt, (SQLCHAR*)"INSERT INTO acid_table VALUES (?, ?)", SQL_NTS);
    int id = 3;
    std::string name = "Charlie";
    S

C++与Hive、Spark、libhdfs、ACID交互技巧