哪一个更快，为什么？-函数内部和外部的php连接

Question

I am working on a PHP project I found there are two ways to make database connections one is from inside of a function and another one is from outside of the function. as follows.

<?php
function_connect1();
function_connect2();
?>

The function_connect1 and 2 is in a separate file called functions.php its as follows.in at this snippet I am making connection each time the function is being called.

<?php
//Function connect1
    function function_connect1(){
    $db_vars=(VARS);
    $connection=mysqli_connect($db_vars);
    //Functions objectives
    mysqli_close($connection);
    }
//Function connect2
    function function_connect2(){
    $db_vars=(VARS);
    $connection=mysqli_connect($db_vars);
    //Functions objectives
    mysqli_close($connection);
    }
    ?>

The above snippet can be written in at the following way as well open a db connection first time and close the same connection after all the functions are being excicuted.

<?php
$db_vars=(VARS);
$connection=mysqli_connect($db_vars);
function_connect1();
function_connect2();
mysqli_close($connection);
?>

Can anybody can tell me which one is fast and why.

Answer 1

If you want to make more queries to the database server, it is advisable (and faster) to open the connection, run queries and close it after all work is done. Closing and re-opening the connection for each query will be always slower.

Answer 2

1 connection takes X time.
2 connections take 2X time.
10 connections take 10X time.

now you can figure it out yourself