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Multiple indexes on the same column

blessed DBAMar 15 2018 — edited Mar 16 2018

Pre Oracle 12c, you can’t create multiple indexes either on the same column or set of columns in any form. For example, if you have an index on column {a} or columns {a,b}, you can’t create another index on the same column or set of columns in the same order. In 12c, you can have multiple indexes on the same column or set of columns as long as the index type is different. However, only one type of index is usable/visible at a given time. In order to test the invisible indexes, you need to set the optimizer_use_use_invisible_indexes=true.

Here’s an the example:

SQL> CREATE INDEX emp_ind1 ON EMP(ENO,ENAME); SQL> CREATE BITMAP INDEX emp_ind2 ON EMP(ENO,ENAME) INVISIBLE; 
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Added on Mar 15 2018
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