产品概述
基本概念
集群架构
产品优势
应用场景
* INSERT INTO table SELECT ...* INSERT INTO table VALUES(...)
INSERT INTO example_tbl (col1, col2, col3) VALUES (1000, "test", 3.25);
高频次的 INSERT 操作会导致在存储层产生大量的小文件,会严重影响系统性能。INSERT INTO example_tbl VALUES(1000, "baidu1", 3.25)(2000, "baidu2", 4.25)(3000, "baidu3", 5.25);
package demo.doris;import java.sql.Connection;import java.sql.DriverManager;import java.sql.PreparedStatement;import java.sql.SQLException;public class DorisJDBCDemo {private static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";private static final String DB_URL_PATTERN = "jdbc:mysql://%s:%d/%s?rewriteBatchedStatements=true";private static final String HOST = "127.0.0.1"; // Leader Node hostprivate static final int PORT = 9030; // query_port of Leader Nodeprivate static final String DB = "demo";private static final String TBL = "test_1";private static final String USER = "admin";private static final String PASSWD = "my_pass";private static final int INSERT_BATCH_SIZE = 10000;public static void main(String[] args) {insert();}private static void insert() {// 注意末尾不要加 分号 ";"String query = "insert into " + TBL + " values(?, ?)";// 设置 Label 以做到幂等。// String query = "insert into " + TBL + " WITH LABEL my_label values(?, ?)";Connection conn = null;PreparedStatement stmt = null;String dbUrl = String.format(DB_URL_PATTERN, HOST, PORT, DB);try {Class.forName(JDBC_DRIVER);conn = DriverManager.getConnection(dbUrl, USER, PASSWD);stmt = conn.prepareStatement(query);for (int i =0; i < INSERT_BATCH_SIZE; i++) {stmt.setInt(1, i);stmt.setInt(2, i * 100);stmt.addBatch();}int[] res = stmt.executeBatch();System.out.println(res);} catch (Exception e) {e.printStackTrace();} finally {try {if (stmt != null) {stmt.close();}} catch (SQLException se2) {se2.printStackTrace();}try {if (conn != null) conn.close();} catch (SQLException se) {se.printStackTrace();}}}}
rewriteBatchedStatements=true 参数,并使用 PreparedStatement 方式。
目前 Doris 暂不支持服务器端的 PrepareStatemnt,所以 JDBC Driver 会在客户端进行批量 Prepare。
rewriteBatchedStatements=true 会确保 Driver 执行批处理。并最终形成如下形式的 INSERT 语句发往 Doris:INSERT INTO example_tbl VALUES(1000, "tencent1", 3.25)(2000, "tencent2", 4.25)(3000, "tencent3", 5.25);
文档反馈