one of my websites is php+mysql,. Now there is a problem.
there are two data tables: an and B. Table A has 240000 items of data, and Table B now has 24000 items of data.
extract 50 pieces of data from datasheet A, and then generate a html page. It takes about 3 seconds for
to extract 50 pieces of data from datasheet B, and then generate a html page. It takes about 20 seconds.
tables with less data take more time. The extraction code is as follows
<?php
$sql=$empire->query("select * from {$dbtbpre}ecms_rhesis where pote="$navinfor[title]" order by onclick desc limit 50");
while($nr=$empire->fetch($sql)) //
{
$mytitleurl=sys_ReturnBqTitleLink($nr);
$nr2=$empire->fetch1("select * from {$dbtbpre}ecms_poetry where title="$nr[heading]" union select * from {$dbtbpre}ecms_classical_chinese where title="$nr[heading]"");
$mytitleurl2=sys_ReturnBqTitleLink($nr2);
?>
<li><a href="<?=$mytitleurl?>"><?=$nr[title]?></a> - - - <a href="[!--titleurl--]"><?=$navinfor[title]?></a> - - -<a href="<?=$mytitleurl2?>"><?=$nr[heading]?></a></li>
<?php
}
?>the above code extracts 50 items from 24000 data in 20 seconds
< hr ><?php
$sql=$empire->query("select * from {$dbtbpre}ecms_poetry where pote="$navinfor[title]" union select * from {$dbtbpre}ecms_classical_chinese where pote="$navinfor[title]" order by onclick desc limit 50");
$nr3=$empire->fetch1("select * from {$dbtbpre}ecms_poet where title="$navinfor[title]"");
$mytitleurl3=sys_ReturnBqTitleLink($nr3);
while($pr=$empire->fetch($sql)) //
{
$mytitleurl=sys_ReturnBqTitleLink($pr);
$t=$empire->fetch1("select tagid from {$dbtbpre}enewstagsdata where id="$pr[id]"");
$tn=$empire->fetch1("select tagname from {$dbtbpre}enewstags where tagid="$t[tagid]"");
?>
<li><a href="<?=$mytitleurl?>"><?=$pr[title]?></a> - - <a href="<?=$mytitleurl3?>"><?=$pr[pote]?></a> - - <a href="<?=$public_r["newsurl"]?>tags-etagid<?=$t[tagid]?>-0.html"><?=$tn[tagname]?></a> - - <?=esub(strip_tags($pr[newstext]),160,"...")?></li>
<?php
}
?>the above code takes 3 seconds to extract 50 items from 240000 data.
now the question is: why do those with a large amount of data take less time?