Re: Re: Changing the default value of an inherited column
От | Peter Eisentraut |
---|---|
Тема | Re: Re: Changing the default value of an inherited column |
Дата | |
Msg-id | Pine.LNX.4.30.0103302259010.1063-100000@peter.localdomain обсуждение исходный текст |
Ответ на | Re: Re: Changing the default value of an inherited column (Tom Lane <tgl@sss.pgh.pa.us>) |
Ответы |
Re: Re: Changing the default value of an inherited column
Re: Re: Changing the default value of an inherited column |
Список | pgsql-hackers |
Tom Lane writes: > 3. The new column will have a default value if any of the combined > column specifications have one. The last-specified default (the one > in the explicitly given column list, or the rightmost parent table > that gives a default) will be used. This seems pretty random. It would be more reasonable if multiple (default) inheritance weren't allowed unless you explicitly specify a new default for the new column, but we don't have a syntax for this. > 4. All relevant constraints from all the column specifications will > be applied. In particular, if any of the specifications includes NOT > NULL, the resulting column will be NOT NULL. (But the current > implementation does not support inheritance of UNIQUE or PRIMARY KEY > constraints, and I do not have time to add that now.) This is definitely a violation of that Liskov Substitution. If a context expects a certain table and gets a more restricted table, it will certainly notice. > Comments? I'm going to implement and commit this today unless I hear > loud squawks ... If we're going to make changes to the inheritance logic, we could certainly use some more thought than a few hours. If you want to revert the patch that was installed in 7.0 then ok, but the rest is not appropriate right now, IMHO. -- Peter Eisentraut peter_e@gmx.net http://yi.org/peter-e/
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