Tom Lane <tgl@sss.pgh.pa.us> wrote:
> I think this is an artifact of the fact that SQL functions parse the
> whole querystring before executing any of it. Parsing of "DELETE FROM
> a" will result in acquiring ROW EXCLUSIVE lock on a, and then when the
> LOCK commands are executed, you have a lock-upgrade scenario and the
> deadlock is unsurprising.
Thanks. It's a surprise for me :-).
> There was some discussion of changing that awhile ago, but I forget
> what the conclusion was. In any case nothing's been done about it.
We cannot make a package of locking controls in a function under
the current behavior. It would be good to improve this area.
Regards,
---
ITAGAKI Takahiro
NTT Open Source Software Center