Thread: prostgres + java + transactions

Hi!
I have an application (jsp+servlets+beans) in java. It updates rows of a
table of pgsql.

I would like to block the rows and I do it with  "select for update" but if
an other user
tries update the same row then he waits for that the firts user finishes the
instruction.
There is any instruccions for I know the rows blocked.

Thanks