Upgrade from MySQL4 to MySQL5. Will my scripts stop working?

[SuperBaby]

I am currently running PHP 5.2.9 but I am still using MySQL4. I am running a lot of Perl and PHP scripts (that use MySQL database) in my websites. I would like to upgrade to MySQL5 but I worry that my scripts will stop working. Will my scripts stop functioning?

After upgrading and if there are problems, can I switch back to MySQL4?

[InstaCarma_Tech]

Stop the MySQL service and take a backup of all your databases first. Then you can upgrade the MySQL . Note that you will have to recompile PHP after the upgrade.

[SuperBaby]

Thanks for the advice. But do you think it is likely my scripts will give problems after upgrading?

[pjman]

I had the same predicament last year. Should I upgrade MYSQL from 4.0.x to 5, when I had to upgrade PHP to 5? I chose to keep MYSQL 4.0x. I'm about to upgrade next week. From all my research, I here that the jump to MYSQL 4.1x is a pain, but very do-able. And the leap to MYSQL 5, is easy.

I haven't heard anyone report big problems with any scripts of any kind when moving to MYSQL to 5. If you hear anything, I would love to know.

Good Luck....

[PlatinumServerM]

Upgrading from mysql4 to mysql5 sometimes does cause problems with existing databases/scripts. Sometimes it goes smoother than others. Always make full backups just in case and you should be fine if something goes wrong.

[UBERHOST]

Adding to all of the above, I'd say that if you have scripts so outdated that they would be broken by upgrading MySQL, such scripts pose a security hazard to your server.