Trouble using LEFTJOIN when table 2 contains 60,000+ records!

[Antivirus]

I am having BIG problems with pageload times when executing the following query:

PHP Code:

$queryvenues = $db->query_read("
    SELECT " . TABLE_PREFIX . "erc_venue.*, " . TABLE_PREFIX . "dma.* 
    FROM " . TABLE_PREFIX . "erc_venue
    LEFT JOIN " . TABLE_PREFIX . "dma ON " . TABLE_PREFIX . "dma.zipcode = " . TABLE_PREFIX . "erc_venue.venuezipcode
    ORDER BY " . TABLE_PREFIX . "erc_venue.venuetitle
"); 


Just to give you all an idea of my db, the erc_venue table contains more than 1,000 records and the dma table contains more than 60,000 records...

FYI, the function i have created to display the results is as follows:

PHP Code:

function print_venue_row($venue) 
{
        if ($venue['venuecountry'] = 'USA' AND $venue['venuezipcode'] != 0)
        { 
            $venuedma = $venue['dmaname_clean'] . " (" . $venue['rank'] . ")";
        } 
        else 
        { 
            $venuedma = ''; 
        } 

    print_cells_row(array(
        "<a href=\"erc_editvenue.php?venueid=".$venue['venueid']."\">".$venue['venuetitle']."</a>",
        $venue['venuecitystate'],
                $venuedma,
        $venue['venueid'],
        "<a href=\"".$venue['venueurl']."\" target=\"_blank\"><img src=\"../images/buttons/ip.gif\" alt=\"".$venue['venueurl']."\" border=\"0\" /></a>",
        "<input type=\"radio\" name=\"idforaction\" value=\"".$venue['venueid']."\">"
    ));
} 


When executing this query, it can take as long as 122 seconds to load the page! Is there any way I could re-write the query (or the function print_venue_row) more efficiently to help load the page more quickly?

Thanks in advance for your assistance

[Paul M]

What indexes do you have on the tables ?

Can you run in debug mode, and then the explain view, and post the result.

[Antivirus]

Thanks, for dma table, my source is as follows:

  `dmacode` int(10) unsigned NOT NULL auto_increment,
  `zipcode` int(5) unsigned zerofill NOT NULL default '00000',
  `rank` tinyint(2) unsigned zerofill NOT NULL default '00',
  `dmaname_clean` varchar(250) NOT NULL default '',
  PRIMARY KEY  (`dmacode`)

for erc_venue table my source is:

  `venueid` int(6) unsigned NOT NULL auto_increment,
  `venuetitle` varchar(30) NOT NULL default '',
  `venueaddy` varchar(50) default NULL,
  `venuecitystate` varchar(50) default NULL,
  `venuezipcode` int(5) unsigned zerofill NOT NULL default '00000',
  `venuecountry` varchar(20) default 'USA',
  `venueurl` varchar(80) default NULL,
  `venuephone` varchar(12) default NULL,
  PRIMARY KEY  (`venueid`)

and the explain thingie is as follows:

SELECT erc_venue.*, dma.* 
FROM erc_venue
LEFT JOIN dma ON dma.zipcode = erc_venue.venuezipcode

ORDER BY erc_venue.venuetitle
LIMIT 0, 12
id select_type table type possible_keys key key_len ref rows Extra 
1 SIMPLE erc_venue ALL         98 Using temporary; Using filesort 
1 SIMPLE dma ALL         45534   

Time Before: 0.27991 seconds
Time After: 7.76009 seconds
Time Taken: 7.48018 seconds

Thanks!

[Antivirus]

bump

[Adrian Schneider]

Add an index on your zipcode columns (both tables) - this will help a lot.

Also, if you alias your tables - you will no longer have to specify the table prefix all over the place:

PHP Code:

$queryvenues = $db->query_read("
    SELECT erc_venue.*, dma.*
    FROM " . TABLE_PREFIX . "erc_venue as erc_venue
    LEFT JOIN " . TABLE_PREFIX . "dma as dma on (dma.zipcode = erc_venue.venuezipcode)
    ORDER BY erc_venue.venuetitle
"); 


[Antivirus]

Thanks SirAdrian,
that was exactly the problem. I had indexed `dmacode` but needed to also create an index on `zipcode`.

The query SCREAMS now. thanks again


(going to work on using aliases from now on as well)