As I understand it most ceramic knives can be sharpened with diamond stones, grinding compounds, and wheels. The difference in hardness between the ceramic and diamond isn't very large so any serious sharpening, and particularly repairs that involve removing a lot of material, like grinding out nicks, is gong to take a lot more time and effort than working on normal knives.

IMHO ceramic knives are best used where their strong points are a real benefit and the conditions of use are controlled so their weaknesses can be avoided.

In the kitchen they are very useful. They slice, notice I say slice and not chop, through pretty much everything without getting dull. They can be a dream to cut with because they are so sharp. If you always use a cutting board, avoid scraping and chopping with them they can last a very long time with little or no maintenance. On the other hand if you tend to casually toss your knife into the sink or drop them on a tile floor a $300 knife might last thirty seconds.

I have used small ceramic blades in knives and scissors to cut Kevlar. Kevlar has a nasty habit of very rapidly dulling materials softer than ceramics. Ceramics hold up and give you clean and predictable cuts. But you don't use your precious ceramic edged knife or shears for general use. They are too delicate and expensive to use to cut out paper dolls.

IMHO ceramic blades are too delicate to use in a survival situation if other, tougher materials, will do the job about as well for less money and do the job more reliably.