Am 06.07.22 um 07:54 schrieb Andreas Kretschmer:
Am 06.07.22 um 07:44 schrieb Christophe Pettus:
On Jul 5, 2022, at 22:35, Matthias Apitz <guru@xxxxxxxxxxx> wrote:
Internally, in the DB layer, the read_where() builds the row list
matching
the WHERE clause as a SCROLLED CURSOR of
SELECT ctid, * FROM d01buch WHERE ...
and each fetch() delivers the next row from this cursor. The functions
start_transaction() and end_transaction() do what their names
suggest and
rewrite_actual_row() does a new SELECT based on the ctid of the
actual row
SELECT * FROM d01buch WHERE ctid = ... FOR UPDATE
...
UPDATE ...
On first glance, it appears that you are using the ctid as a primary
key for a row, and that's highly not-recommended. The ctid is never
intended to be stable in the database, as you have discovered. There
are really no particular guarantees about ctid values being retained.
I'd suggest having a proper primary key column on the table, and
using that instead.
100% ACK.
Andreas
it reminds me somehow on how people used he OID in old times - and now
we removed the OID completely.
Andreas
--
Andreas Kretschmer
Technical Account Manager (TAM)
www.enterprisedb.com
