>> Another idea is to try an outer join:
>> SELECT child_table.parentid INTO tmp_table
>> FROM child_table LEFT JOIN parent_table
>> ON (child_table.parentid = parent_table.parentid)
>> WHERE parent_table.parentid IS NULL;
>
>There's also
>DELETE
>FROM child_table
>WHERE NOT EXISTS (select 1
>from
Tom Lane <[EMAIL PROTECTED]> writes:
> "Roman F" <[EMAIL PROTECTED]> writes:
>
> > DELETE FROM child_table WHERE parentid NOT IN
> > (SELECT parentid FROM parent_table)
>
> Another idea is to try an outer join:
>
> SELECT child_table.parentid INTO tmp_table
> FROM child_table LEFT
"Roman F" <[EMAIL PROTECTED]> writes:
> ... Executing something like
> the following statement would work, but even with indexes it takes an
> insane amount of time to execute for each of the tables:
> DELETE FROM child_table WHERE parentid NOT IN
> (SELECT parentid FROM parent_table)
Uh, what
I have several large tables (10 million to 200 million rows) that have
foreign keys with each other by *convention*, but no actual FOREIGN KEY
constraints.
Over the course of years, orphaned records (children with no parent) have
accumulated and now I want to clean them up. I can't just create th
