On 2014-02-09 00:49:31 +0000, Thom Brown wrote:
> # ALTER TABLE test ADD COLUMN a decimal DEFAULT 2.22;
> ALTER TABLE
>
> # ALTER TABLE test ADD COLUMN b json DEFAULT '{"a":[1,2,3],"b":[4,5,6]}';
> ALTER TABLE
>
> The output generated by those last 2 statements is:
>
> BEGIN 891
> table "pg_temp_16552": INSERT: id[int4]:1 val[int4]:1 a[numeric]:2.22
> table "pg_temp_16552": INSERT: id[int4]:2 val[int4]:2 a[numeric]:2.22
> table "pg_temp_16552": INSERT: id[int4]:3 val[int4]:3 a[numeric]:2.22
> COMMIT 891
> BEGIN 892
> table "pg_temp_16552": INSERT: id[int4]:1 val[int4]:1 a[numeric]:2.22
> b[json]:{"a":[1,2,3],"b":[4,5,6]}
> table "pg_temp_16552": INSERT: id[int4]:2 val[int4]:2 a[numeric]:2.22
> b[json]:{"a":[1,2,3],"b":[4,5,6]}
> table "pg_temp_16552": INSERT: id[int4]:3 val[int4]:3 a[numeric]:2.22
> b[json]:{"a":[1,2,3],"b":[4,5,6]}
> COMMIT 892
>
> This is showing inserts into the temp table as part of the operation.
> Is that sufficient?
I think it's a good thing for now. We don't have support for DDL
replication so it's not yet that interesting, but having the new values
allows to safely handle things like DEFAULTs that produce
nondeterministic data.
What do you think?
Greetings,
Andres Freund
-- Andres Freund http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training &
Services