I have 3 tables tableA, tableB and tableC and the fields tableA.id, tableB.idA and tableC.idA. I'm using this query (bellow) to call information from the database that has in tableA but tableA.id is not found on tableB.idA and tableC.idA.
SELECT tableA.* FROM tableA LEFT JOIN tableB ON (tableB.idA = tableA.id) LEFT JOIN tableC ON (tableC.idA = tableA.id) WHERE tableB.idA IS NULL AND tableC.idA IS NULL; With a low ammount of data (30 records) I receive the data really fast. However with a greater ammount of data (1800 records) it takes 26 seconds to return data and it consumes 100% of processor. This situation happens when I have all tableA.id registered on tableB.ida or tableC.ida. Any ideas? --------------------------------------------------------------------- Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
