Re: Most efficient way to hard-sort records

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От Miroslav Šulc
Тема Re: Most efficient way to hard-sort records
Дата
Msg-id 446058BB.5090201@startnet.cz
обсуждение исходный текст
Ответ на Re: Most efficient way to hard-sort records  (PFC <lists@peufeu.com>)
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Hi PFC,

the generate_series() seems to be the right thing I need in my scenario
but I didn't figure out how to create a SELECT stattement that will
contain sorted main_table.id in first column and generated series in
second column which I would use to update the main_table.position. Is it
possible? How can I do that? Or is there another approach to employ
generate_series()?

Miroslav Šulc


PFC napsal(a):
>
>> Another version along that line ?
>>
>> # create sequence counterseq start 1;
>> -- (set/reset whenever a counter is needed)
>>
>> # select main_table.*, nextval('counterseq') as position2
>>    into sorted_main_table
>>    from main_table, keytable where main_table.id =
>>    keytable.main_table_id
>>    order by value;
>
>     You could also use generate_series(), but I don't know if it can
> generate unbounded series...
>
> ---------------------------(end of broadcast)---------------------------
> TIP 2: Don't 'kill -9' the postmaster

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