Performance of Parsing JSON and Loading into MYSQL

Performance of Parsing JSON and Loading into MYSQL

I am trying to speed up the performance of this PHP code. I am running it
through the browser on XAMPP using Apache and MYSQL on there.
My problem is that I am reading a very large 2GB JSON file. I cannot read
it in one go as I do not have enough memory and thus I have to read it
line by line
The code reads the JSON line by line. For each line (chunk of JSON data) a
function (Function parse_item) is called which decodes the line of the
JSON and then opens up the mysql database and inserts selected data from
the decoded JSON line and then closes the MySQL database. I know its the
inserting to the database that is causing my performance problems but not
sure what to do.(ie when I remove the database and just echo the decoded
JSON it is much faster)
The code (an abbreviated slice) works but is very slow...................
Can anybody help? I am new to PHP so any explanation in simple terms would
be gratefully received.
Also .......if I ran this from the command line (ie loaded PHP to my PC)
would it run much quicker??
Thanks John
//Parse Function
function parse_item($string) {
$data = json_decode($string);
$uid=($data->JsonScheduleV1->CIF_train_uid);
$stp=($data->JsonScheduleV1->CIF_stp_indicator);
$head=($data->JsonScheduleV1->schedule_segment->signalling_id);
$startlocation=($data->JsonScheduleV1->schedule_segment->schedule_location[0]->tiploc_code);
require('connect_db.php');
mysqli_select_db($mysql_link,"timetable");
mysqli_query($mysql_link,"INSERT INTO railstp (uid,stp,head,startlocation)
VALUES ('$uid','$stp','$head','$startlocation')");
mysqli_close($mysql_link);
if (is_null($data)) {
die("Json decoding failed with error: ". json_last_error());
}
}
$file = 'CIF_PA_TOC_FULL_DAILY_toc-full';
// Slices up the JSON into lines and then
parse_item($string);
//