ср, 25 июл. 2018 г. в 13:08, liviuslivius <liviusliv...@poczta.onet.pl>: > > > > Note: this SELECT may have greater CN then you have stored and it > > means on the next step you may receive records already selected here. > > You merge algorithm should take it into account. > > > > Roman Simakov > > > If transaction is in snapshot isolation mode then problem should not exists > Firebird should provide a way to got last CN from transaction start point > But merge is simple, based on Primary Key ID of the record.
In this case exactly. You wrote about read committed transactions so I made such notation) One more note about your idea. Engine will have to read every record in anycase. But maybe expression index could help. -- Roman Simakov ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel
