Re: Difference between varchar and text?

Craig Ringer <craig@xxxxxxxxxxxxxxx> · Mon, 19 Nov 2012 08:24:35 +0800



    On 11/19/2012 12:57 AM, Vick Khera
      wrote:

    
        On Sun, Nov 18, 2012 at 2:29 AM, Tom
          Lane <tgl@xxxxxxxxxxxxx>
          wrote:

          
            I'd generally recommend using "text" if you
              don't have any interest in

              enforcing a specific length limit.

            
      Will there be any table re-writing if I
        do an alter to change the column type from varchar(N) to text?
         I have some really old (from 2000 and 2001) schemas that have a
        metric boatload of data in them, and I'd like to remove the old
        artificial limit on them.
    
    That depends on the PostgreSQL version. Some changes were made to
    improve that recently; from memory, it used to require rewriting, so
    people would sometimes work around it with (dodgy and unsafe) hacks
    directly to the system catalogs. I'm not sure if "recently" is 9.2
    or 9.3.

    
    -- 
 Craig Ringer                   http://www.2ndQuadrant.com/
 PostgreSQL Development, 24x7 Support, Training & Services