There is a limit, but it's so high, your JIRA will be unusable well before you reach it.
Yes, every custom field has a performance overhead, although the effects vary according to what JIRA is looking at the field for, each type of field has different overheads and it's not a linear calculation - you'll get a different effect adding a select list to one system than another.
General rule of thumb - share fields as much as possible. If you've got more than a couple of hundred, while you may not have performance issues caused by fields, you are heading that way and you should be looking to rationalise the fields down to a more manageable number.
You must be a registered user to add a comment. If you've already registered, sign in. Otherwise, register and sign in.