show the schema of a table in oracle
<p>The following mysql query returns the constraints and the default values along with column_name, is_null and other details - </p>

<p>mysql query - <code>select TABLE_NAME, COLUMN_NAME, COLUMN_DEFAULT, IS_NULLABLE, COLUMN_TYPE, COLUMN_KEY, EXTRA from INFORMATION_SCHEMA.COLUMNS where TABLE_SCHEMA = 'DB_NAME'</code></p>

<p>I want to write a similar query in Oracle, the following query returns data_type and is_null but doesn't return constraints and default values -</p>

<p>Oracle query - <code>SELECT TABLE_NAME, COLUMN_NAME, DATA_TYPE, NULLABLE FROM DBA_TAB_COLUMNS where owner = 'USERNAME'</code></p>

<p>How can I extract those information from an oracle  table. 
Note: I don't want to use describe table </p>