On 01/29/2014 08:21 PM, Pavel Stehule wrote: > second question - is not this functionality too dangerous? If somebody > use it as scheduler, then > > a) can holds connect, session data, locks too long time > b) it can stop on query timeout probably much more early then user expect > > What is expected use case?
It is no more dangerous than plain pg_sleep(). The use case is convenience and clarity of code.
I don't think people will be using it as a scheduler any more than they do with pg_sleep() because it can't cross transaction boundaries.
I am sure so experienced user didn't use it. But beginners can be messed due similarity with schedulers.
I invite a) documented these risks b) opinion of other hackers
Probably when it is used as single statement in transaction, then it can breaks only vacuum
