Re: Need help to implement Primary Key.

Gambhir Singh schrieb am 08.02.2024 um 11:30:

> I have a table with a record count of ~500 million (496,098,390).
> There is no primary key in this table. Now I need to set up a primary
> key on this table. I can't find a way to set up a primary key. I
> tried to add a new column with IDENTITY but it is not allowing null
> value for existing rows and I don't know how to update the unique
> value for existing records.

If you add an identity column, it will automatically be populated


alter table foo
   add id bigint generated always as identity not null;

Once that has finished (which will take some time given the size of the table),
you can add the primary key:

alter table foo
   add constraint pk_foo primary key (id);