An interesting tip at alter table drop column tips for Oracle: unused columns.
I knew about the multi-column syntax for drop column, but the unused columns:
You can also drop a table column by marking it unused and then dropping the column, thusly:
alter table table_name set unused column column_name ;They will appear in the DBA_UNUSED_COL_TABS view.
After that:
alter table table_name drop unused columns ;
You can perform the first statement for a few columns over time, then the last statement will delete them all.
Together with some other views like described in places like oracle – How to check if a column exists before adding it to an existing table in PL/SQL?, you can create nifty scripts for your meta-data maintenance.
–jeroen
via: alter table drop column tips.
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