how to optimize php codes

[arnel9]

is there any way how to optimize php codes?

ex:

$id = mysql_pconnect($localhost, $user, $password) or die(mysql_error());

mysql_select_db($database, $id);
$rs = mysql_query("Select * From table", $id);

do
{
echo $row['field'] . "<br>";
}
while($row=mysql_fetch_assoc($rs));

and what other suggestions if any... to optimize php codes 🙂

[OhLordy]

Well, the first step to optimizing a script is to profile it and find out where the bottleknecks are. Here is a little class I use for just that.

<?php

class timer
{
    var $timers = array();

function timer()
{
    // Nothing
}

function timerStart($name = 'default')
{
    $time_portions = explode(' ',microtime());
    $actual_time = $time_portions[1].substr($time_portions[0],1);
    $this->timers["$name"] = $actual_time;
}

function timerStop($name = 'default')
{
    $time_portions = explode(' ',microtime());
    $actual_time = $time_portions[1].substr($time_portions[0],1);
    $elapsed_time = bcsub($actual_time, $this->timers["$name"], 6);
    return $elapsed_time;
}
}
?>

HTH
Rob

[Natty_Dreadlock]

i think your php does not offer much possibilities to be optimized... u should rather try to optimize your db by e.g. using the correct field types (i.e. no varchar where u just wanna store an integer), split the information (especially if u store great amounts in your db) or by setting up indices for columns u use to retrieve the data (WHERE in the sql query) if u have queries like SELECT FROM db WHERE id=1 then id should have an index in order to improve execution (at least if your table is big enough)... also check if u rellay need all fields in your db when u send SELECT FROM db - maybe u can leave out some of em - in this case u gotta write SELECT columnA, columnB, columnD FROM db in order to leave out columnC..... there r lots of opportunities to set up an efficient database, so plz search google etc. for further info, i just wanted to give some point to start...
hth

[arnel9]

thanks for the help guys.

by the way i try to search in google and i found this site
http://phplens.com/lens/php-book/optimizing-debugging-php.php

and it really helps me in optimizing php code. visit this site it is good coz it explain code optimization....

[drawmack]

actually if you want to optimize a mysql database don't use varchar at all but rather use char and pad the strings. It's much quicker to add/chop the padding in php then it is to use a varchar. The reason is that varchars are stored contiguously and varchars are not so a varchar has to store pointers in with the data where as a char just stores the data.

Another big point is proper indexing. Any field that might be used in a where or order by clause should be indexed. We had a thread here recently where a query took 12 seconds and once the indexing was sorted it only took a fraction of a second.

[Weedpacket]

Originally posted by drawmack
actually if you want to optimize a mysql database don't use varchar at all but rather use char and pad the strings. It's much quicker to add/chop the padding in php then it is to use a varchar. The reason is that varchars are stored contiguously and varchars are not so a varchar has to store pointers in with the data where as a char just stores the data.

Contrast this with PostgreSQL, which stores varchars the same way that it stores chars (contiguously, in fixed-sized blocks), and handles the padding/trimming implicitly.

[drawmack]

I never claimed mysql was better, just explaining how to optimize the platform specified in the original post is all.

[arnel9]

The reason is that varchars are stored contiguously and varchars are not so a varchar has to store pointers in with the data where as a char just stores the data.

yeah! char just store data but there some instances that varchar is good in a certain situation like:

CHAR(4) has a value of '' or 'ab' consumes 4 bytes
VARCHAR(4) has a value of '' consume 1 byte
VARCHAR(4) has a value of 'ab' consumes 3 byte

sometimes the length of the data that we inputted is less than the length of the field in the database. So it consumes less storage.

[maxpup979]

A more generic option might be to take a class in theory of computers...learn to love time complexities...Understanding what causes scripts to run slower, as well as be able to prove correctness...truly one of the more useful classes in Comp Sci

[drawmack]

Originally posted by arnel9
CHAR(4) has a value of '' or 'ab' consumes 4 bytes
VARCHAR(4) has a value of '' consume 1 byte
VARCHAR(4) has a value of 'ab' consumes 3 byte

but the lookups are still slower so if speed is your concern then you would still want to use a char.

[arnel9]

thanks...

i read the tips of the link that i given earlier and i come up with this:

<?php
ob_start();
$id=mysql_connect("host", "username", "password") or die(mysql_error()); 
mysql_select_db("databasename", $id); 
$rs = mysql_query("Select name from table_name", $id) or die(mysql_error()); 
$opt = "<select name='names'>"; 
do { 

$opt.= "<option value='" . $row['name'] . "'>" . $row['name'] . "</option>"; 

} 
while($row=mysql_fetch_array($rs));
echo $opt . "</option>";
unset($opt);
ob_end_flush();
?>

this is based in my understanding on the tips

[arnel9]

i use ob_start() at the beginning of your code. This gives you a 5-15% boost in speed for free on Apache.

echoing multiple times is slower than storing everything in a string and echoing it in one call. This is because echo is an expensive operation that could involve sending TCP/IP packets to a HTTP client. just like the code that posted previously...

hopefully im right....