Question

希望有人可以帮助我，这需要永远，我需要加快速度：

SELECT Col2, Col3 FROM Table1 Where Col1 = Whats in Table1 Col1
UPDATE Table2 SET Col2, Col3 Where Col1 = Whats in Table2 Col1

我正在更新和更新的表没有索引，每个行大约有250万行。

查询每秒处理大约60个条目，并且将花费太长时间才能完成。代码如下：

<?php
 //establish connection to my Database
 $link = mysql_connect('localhost', 'info', 'connect') or die('Could not connect: ' . mysql_error());
 mysql_select_db('test') or die('Could not select database');
 set_time_limit(18000);

 //maintain logged in status
 mysql_query("INSERT INTO `logtest` (`loggedin`, `timesince`) VALUES ('1', NOW());");

 $shere=0;
 $sql = "SELECT UniqueID FROM temp WHERE LongDec IS NULL ORDER BY UniqueID DESC";
 $fcr = mysql_query($sql) or die(mysql_error());
 while($frr=mysql_fetch_array($fcr)){
   $shere=$frr[0];
 }
 mysql_free_result($fcr);


 $sql = "SELECT DISTINCT UniqueID, LocationNum FROM temp WHERE UniqueID >=" . $shere . ";";
 $fcr = mysql_query($sql);

 while($fcrow = mysql_fetch_array($fcr)){
   $sql = "SELECT LatDec, LongDec FROM lotest WHERE UniqueID=" . $fcrow[0] . " AND LocationNum=" . $fcrow[1] . ";";
     $frr = mysql_query($sql);
     $fr = mysql_fetch_array($frr);
     $sql = "UPDATE temp SET LatDec=" . $fr[0] . ", LongDec=" . $fr[1] . " WHERE UniqueID = " . $fcrow[0] . " AND LocationNum=" . $fcrow[1] . ";";
     mysql_query($sql);
     //echo $fcrow[0] . ": " . $fr[0] .  "<br>\n";
     mysql_free_result($frr);
}
 mysql_free_result($fcr);

 //Move data to pool
 mysql_query("TRUNCATE pool;");
 mysql_query("INSERT INTO pool SELECT * FROM temp;");

 mysql_close($link);
?>

使用UniqueID更新选择永远使用mysql的位置

0 个答案: