Implementation of Doris Asynchronous Queries (Using Asynchronous Libraries)

Doris is a high-performance, distributed open-source relational database that provides various query methods, among which asynchronous queries is one of its core features. This section introduces how to use the asynchronous library to implement asynchronous queries.

1. what is 异步查询？

Asynchronous Query is a method of executing queries without blocking the current thread. This approach can improve system concurrency and response speed, enabling applications to handle multiple requests quickly.

2. how to 实现异步查询？

Doris provides an interface named async_query which can be used to implement asynchronous queries. In this interface, you need to specify a request, an execution function, and callback functions for execution success or failure.

-- 使用 async_query 执行异步查询
SELECT * FROM table_name WHERE condition = 'value'
  -> async_query(
      // 请求
      {
        "query": "SELECT * FROM table_name WHERE condition = 'value'",
        "options": {
          "timeout": 30000, // 30 seconds
          "retryCount": 3,
          "retryInterval": 1000
        }
      },
      // 执行函数
      function(err, results) {
        if (err) {
          // 处理错误
          console.error(err);
        } else {
          // 打印结果
          console.log(results);
        }
      }
    );

3. async_query 的参数解释

• query: SQL statement
• options: Additional settings, such as timeout duration, retry count, and interval

4. async_query 的使用场景

Asynchronous queries are suitable for high-concurrency systems to handle multiple requests, as they can avoid single-thread blocking and improve system response speed.

5. async_query 的 pitfall

• Do not execute the same SQL statement repeatedly
• Do not use execution functions that are too time-consuming
• Choose appropriate timeout durations and retry counts

In summary, asynchronous query is a high-performance query method provided by Doris that allows queries to be executed without blocking the current thread, enabling the system to handle multiple requests quickly. By understanding the parameter explanations and usage scenarios of async_query, you can better utilize it to improve application response speed.