Robert Haas wrote: > + * To support parallel sort operations involving coordinated callers to > + * tuplesort.c routines across multiple workers, it is necessary to > + * concatenate each worker BufFile/tapeset into one single leader-wise > + * logical tapeset. Workers should have produced one final materialized > + * tape (their entire output) when this happens in leader; there will always > + * be the same number of runs as input tapes, and the same number of input > + * tapes as workers. > > I can't interpret the word "leader-wise". A partition-wise join is a > join done one partition at a time, but a leader-wise logical tape set > is not done one leader at a time. If there's another meaning to the > affix -wise, I'm not familiar with it. Don't we just mean "a single > logical tapeset managed by the leader"?
https://www.merriam-webster.com/dictionary/-wise -wise adverb combining form Definition of -wise 1 a : in the manner of crabwise fanwise b : in the position or direction of slantwise clockwise 2 : with regard to : in respect of dollarwise I think "one at a time" is not the right way to interpret the affix. Rather, a "partitionwise join" is a join done "in the manner of partitions", that is, the characteristics of the partitions are considered when the join is done. I'm not defending the "leader-wise" term here, though, because I can't make sense of it, regardless of how I interpret the -wise affix. -- Álvaro Herrera https://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services