>Sys(3) is suitable for a random filename - filenames are not created in con >secutive milliseconds. For keys, no. > >Do you have a suggestion? > I can only repeat what you can find in numerous threads on the matter here - either use a separate table to keep the last values of PK's for each table, using mechanism like the NewID procedure in the TasTrade example, or use a combination of stationID+datetime(). There's a function which gives a string based on milliseconds, sys(2015) or something near to it. I've used this (the ib is internal key field; in this case it was used for synchronizing two records in master and subdirectory tables, i.e. it had to be unique) repl ib with subs(sys(2015),2) * and a stupid empty loop until the next millisecond do while sys(2015)="_"+ib endd In your case it would be this IB preceded with stationID. It's based on an assumption that one machine may generate this key only once - and we can wait until the millisecond's end to make sure it's unique.