Re: window functions maybe bug

2009/9/2 Tom Lane <tgl@sss.pgh.pa.us>:
> Pavel Stehule <pavel.stehule@gmail.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.

I can understand it. So I found Joe Celko's bug :)

regards
Pavel Stehule

>
>                        regards, tom lane
>