C++与Hive、Spark、libhdfs、ACID交互技巧
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 #include #include using namespace apache::thrift;using namespace apache::hive::service;std::shared_ptr socket(new TSocket(\"localhost\", 10000));std::shared_ptr transport(new TBufferedTransport(socket));std::shared_ptr 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 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 #include #include 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
