[PHP-DB] Which "select " is fast,thanks....... ?

[張峰銘]

Hi,all friends:

Would you please tell me which script in MySQL is  fast?
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1.      select count(*) from  bk_data  

2.      select count(book_name) from bk_data

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PS.  I have 13000 book records  in this table.....

                        Fongming from Taiwan, thanks