Re: Locking concurrency: select for update vs update

Thanks

after your description I found select name from phone_number_type WHERE
id_phone_number_type=4 for *NO KEY* update (Postgresql 9.3 )

W dniu 2016-06-07 o 15:24, Tom Lane pisze:
> Streamsoft - Mirek Szajowski <m(dot)szajowski(at)streamsoft(dot)pl> writes:
>> Why I can't execute 'select for update' but I can update?
> In recent PG versions, the lock held due to having inserted an FK
> dependent row effectively only locks the key fields of the parent row.
> UPDATE can tell whether you're trying to change the row's key fields,
> and it will proceed if you aren't. SELECT FOR UPDATE has to lock the
> whole row (since it must assume you might be intending to change any
> fields of the row); so it blocks until the FK lock goes away.
>
> regards, tom lane