This is quite possibly a nitpicking issue, but one of the issues I currently face is that the cavern layers aren't open spaced and instead are composed of several columns of rock, resembling some sort of swiss-cheese (or labyrinthic) situation.
Those columns are more problematic than helpful. They block LOS (as such my markdwarfves efficiency is diminished), them make pathing slightly complicated and overall don't allow me to grasp the dimensions of the cavern layers (i.e. how one goes to reach a position).
My current attempts of dealing with this were to simply mine the columns. This turned out to be disastrous, as several floors collapsed on top of my miners, killing most.
I want to know if there are ways to handle this efficiently or if I'm caring too much about meaningless detail.
Best Answer
A way I thought was to take advantage of the fact they are full columns. They connect both the floor and the roof of the caverns. As such, one can channel the columns, assuming there is room in the level above the roof. Another method is to build up/down staircases and then carefully designating (from the top down) for everything to be removed/channeled.
However these methods have different chances of success, and in the most part will result in cave-ins. Mining the columns at floor level is a decent compromise, as long as one understands cave-ins. Unless someone disables them in the configuration files, cave-ins happen when a wall or floor tile loses connection to any adjacent orthogonal element. Dwarves, however, can move in all directions, and so some care should be used when mining columns to prevent mining the floor above the cavern level.
Another method is more effective, although it requires a new world (meaning this has to be thought of at start). Adjusting, in Advanced World Generation, the Cavern Layout Parameters, namely, setting Openness at 100 and Density at 0, will try to create highly open caverns.
There is yet another method, albeit more hackish. Assuming you have DFHack r3 installed, you can use the tiletypes command to selectively delete the stone columns, although it does require a considerable amount of work.
Type the following within tiletypes:
The first command should filter only the wall tiles you selected for digging, the second signals for them to be replaced with floor tiles and the third signals that they should be visible. You can input whatever range you want, although it might be handy if you set a high value for x and y. tiletypes works with the k (Look). Place it in the lower upper left vertex of the "cube".