Question

I have table with around 70 000 rows. There is 6000 rows that i need to find, change, and save (i must do this often, few tiems a week). Curently, i am doing it like this, and it las more than 2 minutes to finish: (any advice? 🙁 )

  $query = mysql_query("SELECT meta_value FROM my_table WHERE meta_key = 'key' AND meta_value LIKE '%something%'")or die(mysql_error());

  $new = "soemthing something";

  while($row = mysql_fetch_array($query)){

    $old = unserialize($row['meta_value']);
    $new_meta_r = str_replace($old['color'],$new,$old);
    $new_meta = serialize($new_meta_r);

    $update_meta = mysql_query("UPDATE my_table SET meta_value = '$new_meta' WHERE meta_key = 'key' AND meta_value LIKE '%something%'")or die(mysql_error());
  }

Answer 1

Here are some ways that can help optimizing :

• Try getting the ID besides the meta_value , and when using update just reffering to the ID.
• Check if you really need to use the entire wildcard or you can make it post or prefixed.

Meaning :

#Full wildcard  

 SELECT * FROM TABLE WHERE COLUMN LIKE '%something%';  

#Postfix wildcard  

 SELECT * FROM TABLE WHERE COLUMN LIKE  'something%';  

 #Prefix wildcard  

SELECT * FROM TABLE WHERE COLUMN LIKE  '%something'; 

• Make sure you’re using the right data types, that varchars are the right size, using int instead of BigInt, etc.
• Try moving the query to a Stored Procedure, Stored Procedures are compiled (SQL Code is not), making them faster than SQL code.