On Mon, Sep 22, 2014 at 10:31 AM, Merlin Moncure <mmonc...@gmail.com> wrote: > On Fri, Sep 19, 2014 at 7:16 AM, Bill Moran <wmo...@potentialtech.com> wrote: >> On Fri, 19 Sep 2014 09:32:09 +0200 >> Marius Grama <marius...@gmail.com> wrote: >>> Can anybody explain me what happens in the background when the alter >>> statement is executed? I've tried it out on a small copy of the table (70K) >>> and the operation completed in 0.2 seconds. >>> Will the table be completely locked during the execution of the ALTER >>> statement? >> >> I share Gavin's concern that you're fixing this in the wrong place. I expect >> that you'll be better served by configuring the middleware to do the right >> thing. > > I'll pile on here: in almost 20 years of professional database > development I've never had an actual problem that was solved by > introducing or shortening a length constraint to text columns except > in cases where overlong strings violate the data model (like a two > character state code for example). It's a database equivalent of "C > programmer's disease". Input checks from untrusted actors should > happen in the application. > > merlin >
I do not have your experience level with data bases, but if I may, I will make an addition. Input checks should also happen in the RDBMS server. I have learned you cannot trust end users _or_ programmers. Most are good and conscientious. But there are a few who just aren't. And those few seem to be very prolific in making _subtle_ errors. Had one person who was really good at replacing every p with a [ and P with { -- There is nothing more pleasant than traveling and meeting new people! Genghis Khan Maranatha! <>< John McKown -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general