Re: [GENERAL] Adding identity column to a non-empty table

[Igal @ Lucee.org]

Melvin,

On 10/15/2017 5:56 PM, Melvin Davidson wrote:

On Sun, Oct 15, 2017 at 8:24 PM, Igal @ Lucee.org <i...@lucee.org 
<mailto:i...@lucee.org>> wrote:

    On 10/15/2017 4:01 PM, Igal @ Lucee.org wrote:


        Hello,

        I'm trying to add an identity column to a table that has
        records (previously had a bigserial column which I removed):


    There is probably a better solution, but the one I came up with is
    to add the column as BIGSERIAL and DROP the SEQUENCE CASCADE,
    SELECT the max(rid) + 1, and then convert the column to IDENTITY:


The correct way to make r_id the primary key would be:

ALTER TABLE  event_log
  ADD COLUMN r_id SERIAL;

ALTER TABLE  event_log
  ALTER COLUMN r_id TYPE BIGINT,
  ADD CONSTRAINT dummy_pk PRIMARY KEY (r_id);

That automatically generates the column as

r_id bigint NOT NULL DEFAULT nextval('dummy_r_id_seq'::regclass),
  CONSTRAINT dummy_pk PRIMARY KEY (r_id)

and creates the appropriate sequence for you.


Does that use the new IDENTITY construct that was added in Postgres 10?  
I do not really care for the PRIMARY KEY constraint.  I just want the 
sequence with the benefits of the new IDENTITY "type".

Thanks,


Igal