data_precision and data_scale Missing from Oracle's all_tab_columns
I do not see NUMBER(12,6) anywhere in your output. That column is simply a NUMBER without precision specificed.

SQL&gt; create table t1(c1 number);

Table created.

SQL&gt; insert into t1 values (0.00025);

1 row created.

SQL&gt; select * from t1;

        C1
----------
    .00025

SQL&gt; select data_length, data_precision, data_scale from  all_tab_columns where table_name = 'T1' and column_name = 'C1';

DATA_LENGTH DATA_PRECISION DATA_SCALE
----------- -------------- ----------
         22

SQL&gt;


Specifying NUMBER is not the same as NUMBER(22,0) or NUMBER(22):

SQL&gt; create table t2(c1 number(22, 0));

Table created.

SQL&gt; select data_length, data_precision, data_scale from  all_tab_columns where table_name = 'T2' and column_name = 'C1';

DATA_LENGTH DATA_PRECISION DATA_SCALE
----------- -------------- ----------
         22             22          0

SQL&gt; insert into t2 values (0.00025);

1 row created.

SQL&gt; select * from t2;

        C1
----------
         0

SQL&gt;  create table t3(c1 number(22));

Table created.

SQL&gt;  select data_length, data_precision, data_scale from  all_tab_columns where table_name = 'T3' and column_name = 'C1';

DATA_LENGTH DATA_PRECISION DATA_SCALE
----------- -------------- ----------
         22             22          0

SQL&gt;