@TechReport{chaudhry:relaxing,
  author = {Geeta Chaudhry and Thomas H. Cormen},
  title = {Relaxing the Problem-Size Bound for Out-of-Core Columnsort},
  year = {2003},
  month = {April},
  number = {TR2003-445},
  institution = {Dept. of Computer Science, Dartmouth College},
  address = {Hanover, NH},
  URL = {ftp://ftp.cs.dartmouth.edu/TR/TR2003-445.ps.Z},
  keywords = {parallel I/O, sorting, out-of-core applications, pario-bib},
  abstract = {Previous implementations of out-of-core columnsort limit the
  problem size to $N \leq \sqrt{(M/P)^3 / 2}$, where $N$ is the number of
  records to sort, $P$ is the number of processors, and $M$ is the total number
  of records that the entire system can hold in its memory (so that $M/P$ is
  the number of records that a single processor can hold in its memory). We
  implemented two variations to out-of-core columnsort that relax this
  restriction. Subblock columnsort is based on an algorithmic modification of
  the underlying columnsort algorithm, and it improves the problem-size bound
  to $N \leq (M/P)^{5/3} / 4^{2/3}$ but at the cost of additional disk I/O\.
  $M$-columnsort changes the notion of the column size in columnsort.}
}