How do i interpret the output of function .Q.w[]?

An example explains it best:

$ rlwrap q
KDB+ 2.7 2011.02.16 Copyright © 1993-2011 Kx Systems
q).Q.w[] 
used| 108432   / bytes malloced
heap| 67108864 / heap bytes available
peak| 67108864 / heap high-watermark in bytes
wmax| 0        / workspace limit from -w param
mmap| 0        / amount of memory mapped
syms| 537      / number of symbols interned
symw| 15616    / bytes used by 537 symbols
q)

Note how .Q.w is simply a pretty print output of \w and the workspace memory footprint from \w 0. 

q).Q.w
k){`used`heap`peak`wmax`mmap`syms`symw!(.”\\w”),.”\\w 0″}
q)\w
108304 67108864 67108864 0 0j
q)