Reinhard Hnat <hnat@logotronic.co.at> writes:
> I would like to know how long it will take until the effects of a
> transaction is visible from outside after a commit statement.
There is no delay.
> Or in
> other words: I have the situation that i have to use data which is
> inserted within a transaction immediately after the transactions is
> committed, but sometimes the new data is not available a this moment (A
> few moments later it is available). Is there any method to check if data
> is ready to be used before 'selecting' it?
I think you may be confused by the MVCC mechanism. A SQL statement will
absolutely see everything that is committed as of the instant of the
"snapshot" it's using. I think what you are describing is probably the
effect of having taken a snapshot just before the commit occurred. See
http://www.postgresql.org/docs/8.2/static/mvcc.html
regards, tom lane