Obtain virtual column formula with SQL
This information can be found in the DATA_DEFAULT column of [DBA|ALL|USER]_TAB_COLUMNS.

Example:

SQL&gt;  create table t1(c1 number, c2 number generated always as (abs(ceil(c1)*2)) virtual);

Table created.

SQL&gt; select column_name, data_default from user_tab_columns where table_name = 'T1';

COLUMN_NAM DATA_DEFAULT
---------- --------------------
C1
C2         ABS(CEIL("C1")*2)