SOS Help: random database record selection

I am using the function below to randomly select from a database and print the results using a template. It works fine when the records are under 1,000. Howver, I am using 100k records. Even though it works, the load time is very slow and it is heavily tasking my server. How can I rewrite this code to excute the task more efficiently with minimum stress on myserver. also the default value of $descript = "3". I want to use of a range of 3 to 5 as the default value. Any help will be appreciated.

function description ($descript = "3") {
		include "config.php";
		mysql_connect("$mysql_server", "$mysql_user","$mysql_pass");
		$getlinks="SELECT * from $words_table order by RAND() limit $descript ";
		$getlinks2=mysql_query($getlinks) or die("Could not get links");
		while ($getlinks3=mysql_fetch_array($getlinks2))
		{
		   $desc = $getlinks3[$words_table_name]." ";
		   print $desc;
		}
	}

Code (markup):

this is the code i use in the config file:

$words_table = "words";
$words_table_name = "text";

Code (markup):

this is the code i use to output the results in the template

<?php description (7);?>

Code (markup):

I will really appreciate your help.
Thanks!!

 

If you pre-filter using a where clause based on an indexed field,
you may be able to speed up the results and also maintain
some randomness, see suggestion below:

function description ($descript = "3") 
{
	include "config.php";
	mysql_connect("$mysql_server", "$mysql_user","$mysql_pass");

	$initial= substr("abcdefghijklmnopqrstuvwxyz",0, rand(0,25));

	$getlinks="SELECT * from $words_table where text like '". $initial . "%' order by RAND() limit $descript ";
	$getlinks2=mysql_query($getlinks) or die("Could not get links");
	while ($getlinks3=mysql_fetch_array($getlinks2))
	{
	   $desc = $getlinks3[$words_table_name]." ";
	   print $desc;
	}
}

Code (markup):

 

thanks...
i tried it but it didnt quite work. any other solutions?

Thanks!

 

How about this:

function description ($descript = "3")
{
	include "config.php";
	mysql_connect("$mysql_server", "$mysql_user","$mysql_pass");
	$num = mysql_num_rows("SELECT * FROM $words_table");
	$rand_num = rand(0, $num);
	$rand_end = $rand_num + $descript;
	while($rand_end > $num) --$rand_end;
	$getlinks="SELECT * FROM $words_table LIMIT $rand_num, $rand_end";
	$getlinks2=mysql_query($getlinks) or die("Could not get links");
	while ($getlinks3=mysql_fetch_array($getlinks2))
	{
	   $desc = $getlinks3[$words_table_name]." ";
	   print $desc;
	}
}

PHP:

I haven't tested it anyway.

 

thanks for you help. the code looks pretty but it didnt work.

anymore suggestions?

 

What did you mean by 'didnt work'?
Did you see any errors?

 

no, it does not generate any errors. it just gives you blank areas where the data is suppose to be.

 

Ah, yeah. My fault.
Here is the fixed one:

function description ($descript = "3")
{
	include "config.php";
	mysql_connect("$mysql_server", "$mysql_user","$mysql_pass");
	$num = mysql_num_rows(mysql_query("SELECT * FROM $words_table")); //my fault
	$rand_num = rand(0, $num);
	$rand_end = $rand_num + $descript;
	while($rand_end > $num) --$rand_end;
	$getlinks="SELECT * FROM $words_table LIMIT $rand_num, $rand_end";
	$getlinks2=mysql_query($getlinks) or die("Could not get links");
	while ($getlinks3=mysql_fetch_array($getlinks2))
	{
	   $desc = $getlinks3[$words_table_name]." ";
	   print $desc;
	}
}

PHP:

 

thanks a lot.
this works in an interesting way. it completely neglects
<?php description (1);?>
and randomly loads up the entire table with 23k entries. but its much faster.
i will like to regulate the output number with
<?php description (1);?>
any more ideas?