Re: _bt_check_unique checks every row in table when doing update??

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От Mats Lofkvist
Тема Re: _bt_check_unique checks every row in table when doing update??
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Msg-id y2qbs738ctm.fsf@algonet.se
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Ответ на Re: _bt_check_unique checks every row in table when doing update??  (Tom Lane <tgl@sss.pgh.pa.us>)
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tgl@sss.pgh.pa.us (Tom Lane) writes:

> > But you really shouldn't need the old tuple to know this since none
> > of the columns present in the unique index are 'set' by the update?
> > I.e. the 'not changing the unique key part' is not data dependent,
> > it is guarantied by the form of the update statement.
>
> (a) that's even further upstream from the index AM, and (b) what about
> BEFORE triggers that change the tuple contents?
>
>             regards, tom lane


Ok, I rest my case. I obviously don't know enough of the
postgres internals to suggest a usable solution for this
problem. Thanks for your quick answers.

      _
Mats Lofkvist
mal@algonet.se

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