sort questions - (nf)

[preece at uicsl.UUCP]

#N:uicsl:12500022:000:1329
uicsl!preece    Feb 22 13:57:00 1984

Some questions on the 4.1 system sort program:

	1. sort uses very little memory (although it is very careful
	to check that it can get the amount it asks for).  This may
	date from pdp-11 days or it might be intentional. Does anyone
	know?  In a sort/merge framework there is a tradeoff between
	the cost of disk access and the exponential behavior of the
	in-memory sort; does the memory size limit reflect a careful
	empirical determination of the optimal point on that tradeoff
	curve, or is it an artifact?  On our 780 the sort runs faster
	if it uses more memory.
	
	2. Has anyone done such experimentation and determined good
	values for the parameters in the program?  The number of
	items that will fit in memory is derived by formula from the
	amount of memory, so just increasing the obvious values may
	not be the best way to go. The space for file buffers during
	the merge phase is involved, too.
	
	3. Does anyone have alternative sort programs for unix? I hacked
	multi-line records into the existing version, but not too
	thoroughly; I'd be interested in a program with that capability
	and with better tailoring of internal parameters to the actual
	data, instead of just rigid guesses.

	4. Is the sort that comes with 4.2 the same as the one in 4.1?
	(Likewise SysV)?

scott preece
ihnp4!uiucdcs!uicsl!preece