Difference between RECYCLEBIN and 'DROPPED' column
In Oracle 10g, we have the concept of RECYCLEBIN, which houses all the dropped objects under a different name (like BIN$%).
At the same time, the DBA_TABLES has a column called 'DROPPED' which indicates whether a table has been dropped, and if it is present in RECYCLEBIN or not.
Now, if I drop a table, then the corresponding row from DBA_TABLES is deleted. What, then, is the significance of the 'DROPPED' column? Practically, it would only have a value of 'NO' (or null maybe), and never a 'YES.'
You are correct in your assessment of the DROPPED column in the DBA_TABLES view. If you drop a table, it no longer appears in the DBA_TABLES view, so the DROPPED column will never show 'YES.' But that was not always the case. In the first iteration of Oracle 10g (before 10.2), when you dropped a table, you could see dropped tables in this view. This became a pain for many people to deal with. Why show me those tables which are in my trash can? Typically, I only care about tables that can actually be used. Oracle's official stance on this was that showing dropped tables "breaks compatibility of these views with older releases." So they classified this problem as bug #3255906, which was fixed in 10.1.0.3 and 10.2.0.1.
This was first published in August 2007