I know that the high water mark is the boundary between used and unused space in a segment and it means that segment space to the left of the high water mark is used, and the space to the right of it is unused.

But I need and example in the real world to absorb what does it mean exactly. Could somebody bring an example that HWM increase a lot and coalse or shrink doesn't help.

How can we adjust HWM for a table again?

Is it more important than no. of extents and other segment parameters?

Do we need to look at HWM daily?

Please clarify the confusion