"Thomas Holmgren" <thm@regnecentralen.dk> writes:
> I have a large number of clients synchronizing with a central database.
> The clients update their local data by polling the database for changes
> at fixed intervals. I need an efficient way of determining if data in a
> table has been changed (either updated, deleted or inserted). Can this
> be achieved without scanning the tables using expensive SQL?
Are the clients continuously connected to the database? If so you could
forget the whole polling concept and make it data-driven (the clients
listen for NOTIFY events sent out by updaters).
regards, tom lane
