Tom Lane d26559dbf3 Teach tuplesort.c about "top N" sorting, in which only the first N tuples ... need be returned. We keep a heap of the current best N tuples and sift-up new tuples into it as we scan the input. For M input tuples this means only about M*log(N) comparisons instead of M*log(M), not to mention a lot less workspace when N is small --- avoiding spill-to-disk for large M is actually the most attractive thing about it. Patch includes planner and executor support for invoking this facility in ORDER BY ... LIMIT queries. Greg Stark, with some editorialization by moi.		2007-05-04 01:13:45 +00:00
..
logtape.c	Update CVS HEAD for 2007 copyright. Back branches are typically not	2007-01-05 22:20:05 +00:00
Makefile	Remove remains of old depend target.	2007-01-20 17:16:17 +00:00
tuplesort.c	Teach tuplesort.c about "top N" sorting, in which only the first N tuples	2007-05-04 01:13:45 +00:00
tuplestore.c	Update CVS HEAD for 2007 copyright. Back branches are typically not	2007-01-05 22:20:05 +00:00