Re: BUG #13863: Select from views gives wrong results
| От | wrb |
|---|---|
| Тема | Re: BUG #13863: Select from views gives wrong results |
| Дата | |
| Msg-id | E113617B-7B2F-45A8-9FE1-52711308E9D3@autistici.org обсуждение исходный текст |
| Ответ на | BUG #13863: Select from views gives wrong results (wrb@autistici.org) |
| Список | pgsql-bugs |
<body class=3D"ApplePlainTextBody" dir=3D"auto" = style=3D"word-wrap: break-word; -webkit-nbsp-mode: space; = -webkit-line-break: after-white-space;">Ooops, forgot to mail the = list.WBegin forwarded = message:From: wrb <wrb@autistici.org>Subject: Re: = [BUGS] BUG #13863: Select from views gives wrong resultsDate: 14. = ledna 2016 10:49:27 SE=C4=8CTo: Haribabu Kommi = <kommi.haribabu@gmail.com>Followup: This query = should show better what's wrong with the optimizer:select a, = count(*) from test group by cube (a);a | count = ---+-------1 | 12 | = 1 | 2(3 = rows)select * from (select a, count(*) from test group by = cube (a)) t where a is null;a | count ---+------- | = 0explain select * from (select a, = count(*) from test group by cube (a)) t where a is null; = &n= bsp; &nbs= p; QUERY PLAN = &n= bsp; &nbs= p; --------------------------------------------------------= ----------GroupAggregate (cost=3D32.79..32.89 rows=3D2 = width=3D4) Group Key: test.a Group Key: () = Filter: (test.a IS NULL) -> Sort = (cost=3D32.79..32.82 rows=3D11 width=3D4) = Sort Key: test.a = -> Seq Scan on test = (cost=3D0.00..32.60 rows=3D11 width=3D4) = &n= bsp;Filter: (a IS NULL)The predicate "a is null" in the = outer select should refer to results of inner select and should = therefore return (null, 2) instead of no rows, = right?W=
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