[SQL] Inherits is not encouraged?

2009-03-09 Thread Emi Lu

Good morning,

I have two questions about inherits under postgreSQL 8.0.15.


(1) Is possible that I could change the column of a table that is 
defined by Inherits?


e.g., t1(col1, col2, col3); create table tx(colx) Inherits (t1)
I'd like to get tx shown as (col1, colx, col2, col3).


(2) Logically, I have a table inherited from two other tables, but no 
more other columns. Will it not be encouraged to do so?


e.g., t1 (col1... coln)
 t2 (col1... coln)

 create t3() Inherits (t1, t2) without OID


Thanks a lot!
Lu Ying



--
Sent via pgsql-sql mailing list ([email protected])
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-sql


Re: [SQL] Inherits is not encouraged?

2009-03-09 Thread Tom Lane
Emi Lu  writes:
> (1) Is possible that I could change the column of a table that is 
> defined by Inherits?

> e.g., t1(col1, col2, col3); create table tx(colx) Inherits (t1)
> I'd like to get tx shown as (col1, colx, col2, col3).

No, you don't really have a lot of control over that.  It'll stick
non-inherited columns at the end.

> (2) Logically, I have a table inherited from two other tables, but no 
> more other columns. Will it not be encouraged to do so?

> e.g., t1 (col1... coln)
>   t2 (col1... coln)
>   create t3() Inherits (t1, t2) without OID

Sure, that's allowed.

regards, tom lane

-- 
Sent via pgsql-sql mailing list ([email protected])
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-sql