Edoardo Panfili <edoardo(at)aspix(dot)it> writes:
> I spend many time to explain the bahaviour of the system:
> I some occasions the system use another connection to retrieve some
> information during the main connection. This explain the hangs but...
> why sometimes the system works.
> I do more tests.
Try turning on statement logging in the server. Looking at the sequence
of SQL commands actually issued to the server by the different clients
would probably be informative.
regards, tom lane