[A1,B1],[A1,B2],[A2,B1],[A2,B2]  (variants over 2 fields)


##</code><code>##

record 1 - contains [A1,B1]
record 2 - contains [A1,B2]
record 3 - contains [A2,B1]

##</code><code>##

record 1 - [A1,B1]
record 2 - [A2,B2]