On Thu, Sep 05, 2013 at 11:07:43AM +0800, wangs...@highgo.com.cn wrote: > ??? 2013-09-04 19:30, Noah Misch ??????: >> On Wed, Sep 04, 2013 at 12:08:48PM +0800, wangs...@highgo.com.cn >> wrote: >>> I find that it takes a long time when I increase the scale of a >>> numeric >>> datatype. >>> By checking the code, I found that's because it needs to rewrite >>> that >>> table's file. >>> After checking that table's data file, I found only parameter >>> n_header >>> changed. >>> And, I found the data in that numeric field never changed. >>> So I thank It's not necessary to rewrite the table's file in this >>> case. >> > > Noah Misch <n...@leadboat.com> wrote: >> n_header is part of the numeric field's data. That's not just >> pedantry: the >> display scale stored in n_header affects how numeric_out() formats the >> value. > > Thanks for your reply. > > Just because of what you said, I think increasing scale only lead to > differently > diaplay. There's no difference between 5.25 and 5.2500 in use. > So thers's no need to rewrite the table.
Right or wrong, our numeric type caters to applications that do care about the difference between those outputs. I grant that others do not care. -- Noah Misch EnterpriseDB http://www.enterprisedb.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
