Re: feature request - adding columns with default value

On Fri, 4 Apr 2003, Diogo de Oliveira Biazus wrote:

> Henrik Steffen wrote:
>
> >hello,
> >
> >when doing an "alter table blub add column blah int2"
> >and then issuing an "alter table blub alter column blah set default 0"
> >I will always have to manually "update blub set blah=0" to initialize
> >all existing records.... this is quite annoying while performing this
> >update on a running database with 100 simultaneous clients accessing
> >the database and about 443482 rows in the table.
> >
> >it takes about 10 minutes to perform this update, and for about 6 minutes
> >all other updates to the table are in status "waiting", this leads to
> >a very high load and all max_connection setting is reached soon
> >(on a Dual-Xeon 2.4 GHz machine with 2 GB RAM)
> >
> >i would suggest to change the "alter table add column" function to
> >adding a default value while adding the column if this is possible
> >and if this minimizes "down-time".
> >
> >thank you
> >
> >
> Maybe I'm wrong, but this feature was supported in 7.1,
> and it was removed in 7.2.
> If what I'm saying is true, I would like to know why was this feature
> removed?

AFAIR, some older versions accepted the syntax but then totally ignored
the extra attributes (ie, you could say something like int2 default 0, but
the default was just silently lost).