glibc updates

Hello. 

1.    In my Red Hat customer Portal, If I have the setting "Auto Errata Update" set to yes, -correct me if I am wrong- the system will automatically update any updates. It is my understanding that glibc and kernel changes will need a restart. if the updates are applied because the setting is set to yes, how will I know it needs to be rebooted. Will it do it itself? Can I reboot it from the customer portal? Sorry I am fairly new to red hat in general. 

2. is it safe to leave "Auto Errata Update" to yes in a production environment? 

Thanks, 

Joseph