Possible memory leak with connection.execute or I lack understanding of connection.execute

Hi

I wrote a nodejs script to generate 30M records and insert periodically using the mysql2 driver with promise.

Here is the cut down code. This runs out of heap and crashes when I use the connection.execute. However it works fine when I use the connection.query.

'use strict'
const mysql2 = require("mysql2/promise");
const util = require("util");
async function generateLargeRecordset(limit){
    const insertPrefix = "INSERT INTO SOME_LARGE_TABLE (col1,col2,col3, col4) VALUES ";
    const connection = await mysql2.createConnection({
        host: 'localhost',
        user: 'root',
        password: 'password',
        database: 'database'
    });
    const insertArray = [];
    for(let i=0;i<limit;i++){
        insertArray.push(util.format(`(col1${i},col2${i},col3${i},col4${i})`));
        if(insertArray.length >= 1000){
            let query = insertPrefix + insertArray.join(',') + ';';
        // let result = await connection.execute(query); // <== heap memory issue. crashes when it runs out of heap
        // let result = await connection.query(query); //<== No heap memory issue
            insertArray.length = 0;
        }
    }

    if(insertArray.length >= 0){
        let query = insertPrefix + insertArray.join(',') + ';';
        // let result = await connection.execute(query); // <== heap memory issue. crashes when it runs out of heap
        // let result = await connection.query(query); //<== No heap memory issue
        insertArray.length = 0;
        const used = process.memoryUsage().heapUsed / 1024 / 1024;
        // The memory usage keeps increasing with the execute function
        console.log(`The script uses approximately ${Math.round(used * 100) / 100} MB`);
    }

}

generateLargeRecordset(10000000).then(()=>{
    process.exit(0);
}); 

[jspatel]

It makes sense that execute could be expensive. But it doesn’t explain why application is not releasing any memory from the application side when there are no binding variables (?) for the parameters, hence there is no need to prepare a statement. I will test it out and post my results.

[sidorares]

e when there are no binding variables (?) for the parameters, hence there is no need to prepare a statement

It’s still prepared. It’s like compiling a C++ command line utility, even when intent is to start it without command line arguments it worth compiling upfront so it starts faster