X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=doc%2Ftransformation.texi;h=9225ca80009fb325b71206114aff0c12ea2b962c;hb=6ccbd384363db2e304ffe8cc51fcd2eac0a5349a;hp=0050f9989fc27631880cd93de06e405cb5054255;hpb=d457a40c9a814b7faea9b3fff43d4845f6c84231;p=pspp diff --git a/doc/transformation.texi b/doc/transformation.texi index 0050f9989f..9225ca8000 100644 --- a/doc/transformation.texi +++ b/doc/transformation.texi @@ -527,11 +527,17 @@ are sorted in ascending order. To override sort order, specify (D) or for ascending order. These apply to the entire list of variables preceding them. +The sort algorithms used by @cmd{SORT CASES} are stable. That is, +records that have equal values of the sort variables will have the +same relative order before and after sorting. As a special case, +re-sorting an already sorted file will not affect the ordering of +cases. + @cmd{SORT CASES} is a procedure. It causes the data to be read. @cmd{SORT CASES} attempts to sort the entire active file in main memory. -If main memory is exhausted, it falls back to a merge sort algorithm that -involves writing and reading numerous temporary files. +If workspace is exhausted, it falls back to a merge sort algorithm that +involves creates numerous temporary files. @cmd{SORT CASES} may not be specified following TEMPORARY. @setfilename ignored