Sorry, I guess I wasn't clear.
I have an existing table in my DB, and it doesn't have a column with serial values (actually it did originally, but due to later deletions of about 2/3 of the rows the column now has "holes"). I realize I could add a new serial column, but prefer not to change table + the new column would also become nonconsecutive after further deletions. The nice thing about Oracle's "rownum" is that it' a pseudo-column", not a real one, and AFAIK is always valid.
Suggestions?
-- Shaul
2009/10/13 Grzegorz Jaśkiewicz
<gryzman@gmail.com>
On Tue, Oct 13, 2009 at 4:17 PM, Shaul Dar
<shauldar@gmail.com> wrote:
Hi,
I am running performance simulation against a DB. I want to randomly pull different records from a large table. However the table has no columns that hold sequential integer values (1..MAX), i.e. the columns all have "holes" (due to earlier filtering).
what do yo umean ? you can restrict range of integer column (or any other type) with constraints, for instance CHECK foo( a between 1 and 100);
Also PG does not have a concept of an auto-increment pseudo-column like Oracle's "rownum". Any suggestions?
not true - it has sequences, and pseudo type serial. Rtfm!.
--
GJ