Q:

How to dump huge csv data (4GB) into mysql

If anyone had tried this before using Go, please get the idea with code, that would be really appreciated. 
I wrote few line which is slow
// This is to read the csv file 
func usersFileLoader(filename string, channel chan User) {
    defer close(channel)
    file, err := os.Open(filename)
    if err != nil {
        panic(err)
    }
    defer file.Close()
    var user User
    reader := csv.NewReader(file)
    for {
        err := Unmarshal(reader, &user)
        if err == io.EOF {
            break
        }
        if err != nil {
            panic(err)
        }
        channel <- user
    }
}

// This is to insert csv file
func saveUser(channel <-chan User, db *sql.DB) {
    stmt, err := db.Prepare(`
        INSERT INTO Users( id, name, address) values ( ?, ?, ?)`)
    if err != nil {
        log.Fatal(err)
    }

    for usr := range channel {
        _, err := stmt.Exec(
            usr.ID,
            usr.Name,
            usr.Address,
        )
        if err != nil {
            log.Fatal(err)
        }
    }
}

// here is the struct of the user
type User struct {
    ID      int `csv:"id"`
    Name    int `csv:"name"`
    Address int `csv:"address"`
}

// here is my main func
func main() {
    db := DBconnect(ConnectionString(dbConfig()))
    channel := make(chan User)
    go usersFileLoader("../user.csv", channel)
    saveUser(channel, db)
    defer db.Close()
}

// This code is working but slow for me. 
Share your thought and ideas

A:

I wouldn't attempt to use Go's built in standard library functions for loading a very large CSV file into MySQL (unless, of course, you are simply trying to learn how they work).
For best performance I would simply use MySQL's built in LOAD DATA INFILE functionality.
For example:
result, err := db.Exec("LOAD DATA INFILE ?", filename)
if err != nil {
    log.Fatal(err)
}
log.Printf("%d rows inserted\n", result.RowsAffected())

If you haven't used LOAD DATA INFILE before, note carefully the documentation regarding LOCAL. Depending on your server configuration and permissions, you might need to use LOAD DATA LOCAL INFILE instead. (If you intend to use Docker containers, for instance, you will absolutely need to use LOCAL.)

