Psycopg; How to detect row locking?

[Alban Hertroys]

Istvan Albert wrote:
> Alban Hertroys wrote:
> 
>> I'm also not sure whether I'm actually looking at the same 
>> transaction. Is there a way to verify such?
> 
> Are you using the same connection across threads or the
> same cursor?
> 
> Transactions happen per cursor. They get committed when you call
> the commit() on the cursor (and you probably should not share the cursor
> across threads).

Ok, that means I'm looking at different transactions. That's an 
important distinction...

> Not so along ago there was a similar post. In both, the posters were
> using a mulithreaded database system, postgresql within a mulithreaded 
> program
> yet at the same time desperately trying to fully control the database
> threads from the program threads, both hoping that transactions
> will save the day. But that is not what transactions are about. 

One of those posters was probably me... I'm still kind of stuck on the 
problem, but now knowing that I'm looking at different transactions I am 
pretty sure that I should try a different approach.

> Transactions are
> simply a way to ensure that a series of database instructions
> (within a thread) either all execute or none of them do. One can
> always try to coerce them to do something fancier or more different
> but then quality of the solution shows this.

Which would have been the case if I were looking at a single 
transaction. But apparently that's not the case. Thank you very much for 
your help, now at least I know where I should look.

Alban.