ID: 40261
Comment by: bloire at citytoo dot com
Reported By: thuejk at gmail dot com
Status: Assigned
Bug Type: Performance problem
Operating System: All
PHP Version: 5.2.0
Assigned To: dmitry
New Comment:
Real example ($a_output is a reference with 3000 results from mysql)
The probleme processing with memory is after these differents
solutions
Time for processing Solution 1 or 2 is not verry different.
The real probleme is after Solution 1 or 2 for all other processing
with memory !
$a_input[idlg] = $a_context[idlg];
node::select_node_no_finalsite($a_input,$a_output);
foreach ($a_output as $i => $a_row) {
/*
//Solution 1 : KO because verry verry verry SLOW
$a_data[a_formulaire][listenode2][$i][idn] = $a_row[idn];
$a_data[a_formulaire][listenode2][$i][traduction_idn] =
$a_row[traduction_idn];
$a_data[a_formulaire][listenode2][$i][traduction_idcat]=
$a_row[traduction_idcat];
$a_data[a_formulaire][listenode2][$i][idte_idn] = $a_row[idte_idn];
$a_data[a_formulaire][listenode2][$i][idte_idcat] =
$a_row[idte_idcat];
$a_data[a_formulaire][listenode2][$i][idcat] =
$a_row[idcat];
$a_data[a_formulaire][listenode2][$i][name] = $a_row[name];
$a_data[a_formulaire][listenode2][$i][idsite] =
$a_row[idsite];
*/
//Solution 2 : OK :-) 15 milliseconds
$a_data[a_formulaire][listenode2] = $a_row;
}
//Times here depends choice at top lines !!!
//Times is 6518 milliseconds if solution 1 KO :-(
//Times is 16 milliseconds if solution is 2 OK
$instance_time=new time;
$instance_time->execute("test","start");
for($i=0;$i<50000;$i++){
$a .= "k";
}
//print $a;
$instance_time->execute("test","stop");
print $instance_time->show();
Verry stange behavior for only 50000 concats !!!!!!!!!!!
It's not normal because no probleme before php < 5.2
Previous Comments:
------------------------------------------------------------------------
[2007-03-16 13:35:53] bloire at citytoo dot com
My version is 5.2.1 the lastest with mandake limited edition 2005 and
fedora core 4
The probleme exist always with php 5.2.1 !!!!!!!!!!! The latest release
!
Probleme looks like :
function test(&$b){
//sql Query...
//$a_result_mysql
//No problem with performance with php 5.2.1 (6 secondes)
foreach($a_result_mysql as $i=> $a_row) {
$b[artist][item][$i] = $a_row;
}
//Very very very very very very very very very slow with php 5.2 (180
secondes)
//normal with php < 5.2 (10 secondes)
foreach($a_result_mysql as $i=> $a_row) {
$b[artist][item][$i][name] = $a_row[name];
$b[artist][item][$i][firstname] = $a_row[firstname];
$b[artist][item][$i][address] = $a_row[address];
$b[artist][item][$i][zip] = $a_row[name];
$b[artist][item][$i][color] = $a_row[color];
}
}
test($b);
------------------------------------------------------------------------
[2007-03-16 13:02:56] bloire at citytoo dot com
I have exactly the same probleme with foreach with big rows from mysql
and reaffection for each field for each row
After that, all processing is verry verry verry VERRY slow. It's
HORRIBLE. It's verry strange because I didn"t have this probleme with
php < 5.2
I hope that will be repair because now, I'm not trusting with php 5.2
Thank you for all
------------------------------------------------------------------------
[2007-03-16 12:09:04] thuejk at gmail dot com
I think I am hitting this in practice, or something like it.
I have a function call
<?
function lala() {
[database access with lots of data]
echo "returning " . time();
return;
}
lala();
echo "returned ".time();
?>
And I can see that for some reason, the time between "returning" and
"returned" is 60 seconds! This only happens the first time this
function is called, for some reason. Installing php 5.1.6 it returns
instantaneously.
I liked thet PHP 5.1 memory allocator better :(. The PHP 5.1 memory
allocator was also 1/4 the size of the PHP 5.2 memory allocator.
------------------------------------------------------------------------
[2007-01-30 14:53:40] thuejk at gmail dot com
The latest PHP snapshot does fix my example, and probably makes my
production code work.
This will probably fix the problem in far most cases. But it is
possible to construct an example which still have the problematic
behavior. One example is below.
<?php
$num = 100000;
$a = Array();
for ($i=0; $i<$num; $i++) {
$a[$i] = Array(1);
}
for ($i=0; $i<$num; $i++) {
$b[$i] = $a[$i][0];
}
unset($a);
for ($i=0; $i<$num; $i++) {
$b[$i] =
"1234567890123456789012345678901234567890123456789012345678901234567\
8901234567890123456789012345678901234567890123456789012345678901234567890123456\
7890123456789012345678901234567890123456789012345678901234567890123456789012345\
6789012345678901234567890123456789012345678901234567890123456789012345678901234\
5678901234567890";
}
?>
------------------------------------------------------------------------
[2007-01-30 14:03:32] [EMAIL PROTECTED]
Please try PHP_5_2 snapshot. It already uses litle bit different
"best-fit" implementation and this script takes reasonable time (near
the same as 5.1).
------------------------------------------------------------------------
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