Re: updateable cursors & visibility
От | Peter Eisentraut |
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Тема | Re: updateable cursors & visibility |
Дата | |
Msg-id | Pine.LNX.4.44.0303251735370.1651-100000@peter.localdomain обсуждение исходный текст |
Ответ на | Re: updateable cursors & visibility (Neil Conway <neilc@samurai.com>) |
Ответы |
Re: updateable cursors & visibility
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Список | pgsql-hackers |
Neil Conway writes: > 11) If an <updatability clause> of FOR UPDATE with or without a <column > name list> is specified, then INSENSITIVE shall not be specified and QE > shall be updateable. > > I'm not really sure I see the point of this restriction, though... If you allow updatable insensitive cursors, then you are really saying, whatever happens in the rest of the world does not affect my cursor, but what I do in my cursor affects the rest of the world. You can easily construct some cases where this would have bizarre results. For example, someone inserts a primary key into the underlying table. You don't see it in the cursor, so you happily insert the same primary key. How can you and when should you detect this error? Also, since the snapshot of insensitive cursors is frozen when the cursor is created, would you insert new rows "in the past"? It's not really workable when you think it through. -- Peter Eisentraut peter_e@gmx.net
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