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rohanpinto · 11-22-2007, 09:31 AM

logging slow queries on this DB.. here's what I got:
(a few examples)

SELECT keyword from content where adult<>"yes" and type='public' order by rand() ASC LIMIT 0, 25;
# Time: 071122 4:18:34
# User@Host: username[username] @ localhost []
# Query_time: 2 Lock_time: 0 Rows_sent: 0 Rows_examined: 79270

SELECT * from content where type='public' and (keyword like '%harbhajan%' or keyword like '%mann%'or keyword like '%man%'or keyword like '%jatt%'or keyword like '%sam%'or keyword like '%latest%'or keyword like '%punjabi%'or keyword like '%song%'or keyword like '%mitti%'or keyword like '%wajan%'or keyword like '%mardi%'or keyword like '%wajde%'or keyword like '%dhol%'or keyword like '%naal%'or keyword like '%algose%'or keyword like '%tumbi%'or keyword like '%upload%'or keyword like '%miti%'or keyword like '%vaja%'or keyword like '%vajan%') and adult<>"yes" order by VID asc limit 14619, 5;
# Time: 071122 4:20:03
# User@Host: username[username] @ localhost []
# Query_time: 2 Lock_time: 0 Rows_sent: 10 Rows_examined: 79685

rohanpinto · 11-22-2007, 10:02 AM

i modified my table and added:

KEY `INDEX` (`adult`,`featured`,`type`,`addtime`)

still no use....

here's my PHP select statements:
$sql1="SELECT * from content where type='public' and adult='yes' and featured='yes' order by addtime desc limit 12";
$rs1=$conn->Execute($sql1);
if($rs1->recordcount()>0)
$featuredcontent = $rs1->getrows();
STemplate::assign('featuredcontent',$featuredconte nt); ---> i use smarty for the presentation...

sterin · 11-22-2007, 10:10 AM

And your last query didn't gain speed?

As for the two others.
1.
Try not to use negations like adult <> 'yes'.
Change them to adult = 'no' instead.
Index usage is much improved.

2.
An "... ORDER BY RAND()" can not use an index. Hence it will always require CPU to order the records. But note that the amount of records that needs sorting is determined from how many that match the WHERE and/or that are left after a GROUP BY statement since sorting is one of the last steps in a query execution.
The only thing you can do to speed this query up is to make sure that you have a sort_buffer_size setting that is large enough to store the temporary table in RAM instead of having to write it to disk.

rohanpinto · 11-22-2007, 10:25 AM

didnt help... here's what I have now:

1 PHP page:
content as follows:

include("include/config.php");
include("include/function.php");
$mydate= date('Y-m-d');

$sql="SELECT CHID, name from channel";
$rs = $conn->Execute($sql);
$channels = $rs->getrows();
STemplate::assign('channels',$channels);

if($_SESSION['filterstatus']=="on"){
$sql1="SELECT * from content where type='public' and (adult<>'yes' or adult is NULL) and featured=\"yes\" order by addtime desc limit 12";
} else {
$sql1="SELECT VID, title, from content where type='public' and adult='yes' and featured='yes' order by addtime desc limit 12";
}
$rs1=$conn->Execute($sql1);
if($rs1->recordcount()>0)
$featuredcontent = $rs1->getrows();
STemplate::assign('featuredcontent',$featuredconte nt);

STemplate::assign('page', 'index');
STemplate::display('head.tpl');
STemplate::display('err_msg.tpl');
STemplate::display('index.tpl');
STemplate::display('footer.tpl');
?>

here's my function.php
function insert_id_to_thumb($a)
{
global $config,$conn;

$VID=$a[vid];
$provider=$a[provider];
$flvdoname=$a[flvdoname];
$img=$a[img];
if($img=="") $img=rand(1, 3);
if($provider=="yt") $thumburl="http://img.youtube.com/vi/".$flvdoname."/".$img.".jpg";
elseif($provider=="myspace") $thumburl="http://myspaceurl.com/vi/".$flvdoname."/".$img.".jpg";
else $thumburl="/thumb/".$img."_".$VID.".jpg";
return $thumburl;
}

function insert_video_channel($a)
{
global $conn;
if($a[tbl]=="")$sqlx="channel from content where VID='$a[vid]'";
else $sqlx="channel from $a[tbl] where GID='$a[gid]'";
$sql="select $sqlx";
$rs=$conn->execute($sql);
$a=$rs->fields[channel];
if($a!="")
{
$temp=explode("|",$a);
if(count($temp)>=1) for($i=1;$i $sql="select CHID,name from channel where CHID=$temp[0] $list";
$rsx=$conn->execute($sql);
$res=$rsx->getrows();
return $res;
}
}

function insert_comment_count($a)
{
global $conn;
$sql="select count(*) as ttl from comments where VID='$a[vid]'";
$rs=$conn->execute($sql);
return $rs->fields[ttl];
}

?>

and here's my index.tpl (smarty template)
{section name=i loop=$channels}

rohanpinto · 11-22-2007, 02:02 PM

HELP !!! anybody !! somebody !!

sterin · 11-22-2007, 03:19 PM

Please don't post a lot of PHP code because it really doesn't say anything.

Do as you did posting the CREATE TABLE and then post the specific query that takes time and the explain plan for it.

As for your CPU usage it is 7.5% not 29%. If you look at the top of the "top" output it says

Cpu(s): 3.1%us, 4.4%sy, 0.0%ni, 92.5%id, 0.1%wa, 0.0%hi, 0.0%si, 0.0%st

which means that 7.5% is used and 92.5% is idle.

The reason why mysqld is reporting 29% in the list is that the mysql process is in fact a _lot_ of threads and a rounding error for each thread makes the cpu usage to rise. But that is purely a display problem.
The summarized cpu usage for the system is what you should look at and 7.5% isn't that high.

mikec · 11-22-2007, 07:30 PM

One comment on the table design...

Recommend splitting the table up so that there is a main
table with a few commonly accessed fields and a child (dependent)
table that has all the less commonly accessed fields. The goal
is to slim down the number of columns in the main table.

The row size is sooo big for this table that it will be
slow to search as not many rows can be packed into a 16k
block with a large row like this. This means that it will
take a lot of disk accesses to search this table. Making
it skinnier will improve search speed.

You would want to put any fields that are searched for in
the main table, or any fields that are always accessed in
the main table.

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