Huge threads ok or not?

[NokStar]

I got some people posting threads and making them go long and long.
Like 5000 replies or 10,000+ so it is affecting the database or system performance. Or is there any disadvantages?
I mean having lot of small threads like 100 posts each and having a hug thread like 10,000 posts have any difference in system resource usage or database redundancy?

In simple term having long threads in bad? if it's let me know how it happen
Let me know the safe size of a thread if it effects the system or database.

Thank you very much!!!

[Jake Bunce]

That should be OK. No matter how long a thread is, each individual page only selects this many posts from the database:

Admin CP -> vBulletin Options -> Thread Display Options (showthread) -> Maximum Displayed Posts Before Page Split