Oracle Database Discussions

currently testing flashback table but i am wondering why recycle bin not showing anything after drop? i check the parameter and the value is on. now it made me think is there a relative relationship between recycle bin, undo retention and undo tbs size?

if so why is it not working on an undo_retention= 900, undo tbs size= 100MB and the table i dropped consist of only 1 column and 3 rows data type number, which is particulary small. is there something i need to set further???

db version is 10.2.0.1.0

Thanks!