Create indexes on NULL columns in oracle databases
November 16th, 2006
As you might know, having a column with NULL values degrades your chances on a well performing oracle database when using the “IS NULL” in the WHERE clause of your SQL. This is because “IS NULL” isn’t a value but actually just “undefined”, and thereby you can’t create a database index on that value.
But no more!
The solution is to use FBI or Function Based Indexes. This can be archived using the NVL function in both the WHERE clause and in the index creation.
See more here: