I just found this unexpected result, those who know how indexing works might understand it but I don't, and it's funny:
I have a large phone listing with over 22 million records. The phone number is a string (varchar 16). There's an index for the first 8 chars of the phone number. Now note the response times when I forget the quotes: mysql> select rec_no,phone_no from White where phone_no='0636941'; +---------+----------+ | rec_no | phone_no | +---------+----------+ | 1860796 | 0636941 | +---------+----------+ 1 row in set (0.06 sec) mysql> select rec_no,phone_no from White where phone_no=0636941; +---------+----------+ | rec_no | phone_no | +---------+----------+ | 1860796 | 0636941 | +---------+----------+ 1 row in set (2 min 47.01 sec) I would have expected the second query to either work quickly, or to fail altogether. I am curious how it succeeded, but failed to use the indexing. I suspect that any insight we get from this could help in optimizing db design and queries in future. Steve -- Steve Rapaport World Citizen --------------------------------------------------------------------- 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
