Florian Weimer <fweimer@xxxxxx> writes: > I run this innocent query > CREATE TABLE foo AS SELECT DISTINCT bar FROM baz ORDER BY bar; > and the resulting table contains duplicate rows. 8-( > According to EXPLAIN, an index scan on the bar column is used (using > the underlying B-tree index). Do you mean an indexscan followed immediately by a Unique node? If so, yeah, that would depend entirely on correct ordering of the indexscan output to produce distinct results. > If I drop the DISTINCT, the output is not correctly ordered, either. > Perhaps this is an index corruption issue? The hardware itself seems > fine. Perhaps. Do you want to save off a physical copy of the index and then try REINDEXing? If that fixes it, I'd be interested to compare the two versions of the index. regards, tom lane
