Re: [HACKERS] Re: [HACKERS] Is it necessary to rewrite table while increasing the scale of datatype numeric？

"wangshuo@highgo.com.cn" <wangshuo@highgo.com.cn> wrote:

> I modified the code for this situation.I consider it very simple.

> It will does not modify the table file, when the scale has been
> increased exclusively.

This patch would allow data in a column which was not consistent
with the column definition:

test=# create table n (val numeric(5,2));
CREATE TABLE
test=# insert into n values ('123.45');
INSERT 0 1
test=# select * from n;
  val  
--------
 123.45
(1 row)

test=# alter table n alter column val type numeric(5,4);
ALTER TABLE
test=# select * from n;
  val  
--------
 123.45
(1 row)

Without your patch the ALTER TABLE command gets this error (as it
should):

test=# alter table n alter column val type numeric(5,4);
ERROR:  numeric field overflow
DETAIL:  A field with precision 5, scale 4 must round to an absolute value less than 10^1.

--
Kevin Grittner
EDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company