Finding matches between two tables, each with 160k+ rows - php

Question

I have two tables each with 160k+ rows each. between the two some UUID are shared. I'm and using a foreach loop over the "new" table with an embedded foreach searching the "old" table. When a UUID match is out the "old" table is updated with data from the "new" table.
Both tables have an index on the ID.
My problem is this operation is extreme time intensive; does anyone know a more efficient way to do said search for matching UUIDs? Sidenote: we are using the MySQLi extension for PHP 5.3
Exp code:
$oldCounter = 0;
$newCounter = 1;
//loop
foreach( $accounts as $accKey=>$accValue )
{
echo( "New ID - " . $oldCounter++ . ": " . $accValue['id'] . "\n" );
foreach( $accountContactData as $acdKey=>$acdValue )
{
echo( "Old ID - " $newCounter++ . ": " . $acdValue['id'] . " \n" );
if( $accValue['id'] == $acdValue['id'] && (
$accValue['phone_office'] == "" || $accValue['phone_office'] == NULL || $accValue['phone_office'] == 0 )
){
echo("ID match found\n");
//when match found update accounts with accountsContact info
$query = '
UPDATE `accounts`
SET
`phone_fax` = "' . $acdValue['fax'] . '",
`phone_office` = "' . $acdValue['telephone1'] . '",
`phone_alternate` = "' . $acdValue['telephone2'] . '"
WHERE
`id` = "' . $acdValue['id'] . '"
';
echo "" . $query . "\n\n";
$DB->query($query);
break 1;
}
}
}
unset($oldCounter);
unset($newCounter);
Thank you in advance.

Answer 1

Do this all in SQL.
There is nothing that I see in your code that requires PHP.
UPDATE allows JOIN. JOIN the new and old tables and have your WHERE conditions match that of your description. Should be pretty straightforward and significantly faster.

Answer 2

I wrote a function some months ago
You can modify it as you want .
This can improve the speed of your search
public static function search($query)
{
$result = array();
$all = custom_query::getNumRows("bar");
$quarter = floor(0.25 * $all) + 1;
$all = 0;
for($i = 0;$i<4;$i++)
{
custom_query::condition("", "limit $all, $quarter");
$data = custom_query::FetchAll("bar");
foreach ($data as $v)
foreach($v as $_v)
if (count(explode($query, $_v)) > 1)
$result[] = $v["bar_id"];
$all += $quarter;
}
return $result;
}
It returns you the ID of the record that search matched on it.
This method divides the table to 4 parts and each iteration gets only a quarter of it...
You can change this number to for example 10 or 20 for speed of...
some methods are in the class and you can easily write theme...