Re: PGSQL or other DB?
От | Scott Marlowe |
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Тема | Re: PGSQL or other DB? |
Дата | |
Msg-id | dcc563d10902010844l78696bd5h703e6356bfafb9f3@mail.gmail.com обсуждение исходный текст |
Ответ на | Re: PGSQL or other DB? (Russ Brown <pickscrape@gmail.com>) |
Список | pgsql-general |
On Sun, Feb 1, 2009 at 7:33 AM, Russ Brown <pickscrape@gmail.com> wrote: > Scott Marlowe wrote: >> >> On Sat, Jan 31, 2009 at 2:13 AM, Erik Jones <ejones@engineyard.com> wrote: >>> >>> On Jan 30, 2009, at 11:37 AM, durumdara wrote: >>> Looking into Firebird I couldn't >>> find how it handles (or doesn't) that at all I but I did see that it will >>> happily let you add a new not null column with no default to a table by >>> writing nulls for the new attribute for any existing columns. That >>> already >>> makes me queasy. >> >> That's pretty much what pgsql does. Why does it make you queasy? >> > > I think the key is that the new column is NOT NULL, so defaulting the new > column's values to NULL results in immediate data integrity inconsistency. > > If I remember rightly, PG doesn't allow this: you have to create the column > as NULL, UPDATE and then add the NOT NULL constraint, or perhaps (I haven't > tried this) create the column with a default and then remove it immediately > afterwards. OK, I completely misunderstood what the other poster meant. Pgsql does NOT allow creating the not null column with nulls in place. That would make me quesy too. Creating it with a default works in postgresql.
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