Re: Unnecessary checks for new rows by some RI trigger functions?

Tom Lane <tgl@sss.pgh.pa.us> wrote:

> Not sure what I think about your new proposed patch.  What problem
> do you think it solves?  Also, don't think I believe this:
> 
> +         * crosscheck_snapshot is actually used only for UPDATE / DELETE
> +         * queries.

I wanted to clarify the meaning of crosscheck_snapshot, i.e. only set it when
it's needed. Anyway I don't feel now it's worth the amount of code changed.

> The commands we're issuing here are SELECT FOR UPDATE^H^H^HSHARE,
> and those should chase up to the newest row version and do a
> crosscheck just as UPDATE / DELETE would do.  If they don't, there's
> a hazard of mis-enforcing the FK constraint in the face of
> concurrent updates.

Maybe I missed something. When I searched through the code I saw the
crosscheck_snapshot passed only to heap_update() and heap_delete().

-- 
Antonin Houska
https://www.cybertec-postgresql.com