Bruce Momjian <pgman@candle.pha.pa.us> writes: > Someone has reported to me that VACUUM ANALYZE is causing different > results for the same query. They believe it is caused by merge join.
Fixed; bug was introduced here: 2005-05-13 17:20 tgl * src/: backend/executor/nodeMergejoin.c, include/executor/execdebug.h, include/executor/execdefs.h, include/nodes/execnodes.h: Revise nodeMergejoin in light of example provided by Guillaume Smet. When one side of the join has a NULL, we don't want to uselessly try to match it against every remaining tuple of the other side. While at it, rewrite the comparison machinery to avoid multiple evaluations of the left and right input expressions and to use a btree comparator where available, instead of double operator calls. Also revise the state machine to eliminate redundant comparisons and hopefully make it more readable too. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings