I understand that MySQL returns the # of rows changed. What I am wondering is if I change only one value, therefore a row change, but leave the rest, what happens. Does the row get removed from the index and re-placed?? Does MySQL look at each column value first to compare?? Mike
----- Original Message ----- From: "sheeri kritzer" <[EMAIL PROTECTED]> To: "MySQL List" <mysql@lists.mysql.com> Sent: November 22, 2005 9:31 AM Subject: Re: UPDATE and INDEX updates Mike, The documentation at http://dev.mysql.com/doc/refman/5.0/en/update.html explains that MySQL is aware of the fact that it only needs to update different values -- for instance, it returns only the # of rows changed, not the # of rows looked at. Given that, I will extrapolate that MySQL is not going to re-work an index unless it actually changes a value. -Sheeri On 11/21/05, Mike OK <[EMAIL PROTECTED]> wrote: > Hi > > I was wondering how the index process worked internally for UPDATE statements. If I was to "set" a value for a column with the UPDATE statement but the value was the same, would MySQL re-work the index?? I can check for data change for each column inside of my code before UPDATE but want to make sure I need to before going ahead. Mike > -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED] -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.1.362 / Virus Database: 267.13.5/177 - Release Date: 2005-11-21 -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
