On Thu, 2022-04-07 at 16:16 +0300, Andrus wrote: > Orders are in table > > create table order ( > dokumnr int primary key, > packno char(10) > ); > insert into order dokumnr values (123); > > One user sets pack number using > > update order set packno='Pack1' where dokumnr=123 > > 3 seconds later other user retrieves pack number using > > select packno from order where dokumnr=123 > > However, other user gets null value, not Pack1 as expected. After some time later, correct value Pack1 is returned. > > How to get updated data from other user immediately? > 3 seconds is long time, it is expected that select suld retrieve update data. > > There are lot of transactions running concurrently. Maybe update command is not written to database if second user retrieves it. > > How to flush orders table so that current results are returned for second user select ? > > Using > PostgreSQL 13.2, compiled by Visual C++ build 1914, 64-bit > and psqlODBC driver.
That cannot happen, unless
a) the UPDATE runs in a transaction that hasn't been committed
b) the SELECT is running on a standby server, and there is replication lag
There's also:
c) The SELECT runs in a transaction stat *started* before the transaction that a runs in. (Assuming it then retries with a new transaction later, that is)
