INTEGER = NUMBER(38)

I noticed something a little strange today.

I've recently been creating tables with as specific a data type as I could. In that regard, I've been using INTEGER.

CREATE TABLE t
(
  x INTEGER
);

Do a describe on that table:

CJUSTICE@TESTING>@DESC T
 Name                                   Null?    Type
 -------------------------------------- -------- ------------
 X                                               NUMBER(38)

Running a query on USER_TAB_COLUMNS results in this:

SELECT
   data_type,
   data_type_mod,
   data_length,
   data_precision,
   data_scale,
   default_length
 FROM user_tab_columns
 WHERE table_name = 'T'
   AND column_name = 'X';

DATA_TYPE  DAT DATA_LENGTH DATA_PRECISION DATA_SCALE DEFAULT_LENGTH
---------- --- ----------- -------------- ---------- --------------
NUMBER                  22                         0

The describe says NUMBER(38) yet USER_TAB_COLUMNS says NUMBER(22). Weird.

When I view the object through the SQL Developer schema browser and go to the SQL tab I get this:

CREATE TABLE "CJUSTICE"."T" 
( 
  "X" NUMBER(*,0)
);

So Oracle converts it somewhere along the way?

Further, going to the source of DBA_TAB_COLUMNS took me to DBA_TAB_COLS, I really thought it was the other way around, but I digress. I began to look at the source from DBA_TAB_COLS which had many staring at all of the SYS tables. OBJ$. COL$. HIST_HEAD$. USER$. COLTYPE$. I then started to try to unravel that...but I stopped.

It obviously won't stop me from doing my work, I just found it interesting. It's similar to A NULL Observation, III.