| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com> |
| Cc: | PostgreSQL Hackers <pgsql-hackers(at)postgresql(dot)org>, ITAGAKI Takahiro <itagaki(dot)takahiro(at)oss(dot)ntt(dot)co(dot)jp> |
| Subject: | Re: window functions maybe bug |
| Date: | 2009-09-02 14:46:54 |
| Message-ID: | 2958.1251902814@sss.pgh.pa.us |
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| Lists: | pgsql-hackers |
Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com> writes:
> create table x1 (a integer);
> insert into x1 values(2),(2),(3),(3),(4),(4),(5),(5),(6),(6),(6),(8),(9),(9),(10),(10);
> postgres=# select row_number() over (order by a), row_number() over
> (order by a desc) from x1;
> row_number | row_number
> ------------+------------
> 16 | 1
> 15 | 2
> 14 | 3
> 11 | 4
> 13 | 5
> 12 | 6
> 9 | 7
> 10 | 8
> 7 | 9
> 8 | 10
> 5 | 11
> 6 | 12
> 4 | 13
> 3 | 14
> 1 | 15
> 2 | 16
> (16 rows)
> I am not sure, is this correct?
I don't see any grounds for arguing that it's wrong. The results for
rows with equal "a" values are indeterminate.
regards, tom lane
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