Rafal Pietrak wrote:
>> You might use 'ctid' to identify the row if you have no suitable
>
> How should I use 'ctid'? Like in the case, when I've selected
> something by means of SELECT ... FOR UPDATE?
You lock the table (with LOCK) or the row you're working on
(with SELECT FOR UPDATE) so that nobody else can change it while
you are working on it.
You need something like ctid if your table has the fundamental flaw
of lacking a primary key.
Sample:
FOR row IN SELECT ctid, * FROM table FOR UPDATE LOOP
UPDATE table SET column=value WHERE ctid=row.ctid;
...
END LOOP;
If your table has a primary key, use that instead and please
forget about the ctid.
Yours,
Laurenz Albe
---------------------------(end of broadcast)---------------------------
TIP 9: In versions below 8.0, the planner will ignore your desire to
choose an index scan if your joining column's datatypes do not
match
