Oracle Database Discussions

Version: 11.2.0.3
OS : RHEL 5.4


In the below table, PRODUCT_SEGMENT_ID column is created with VARCHAR2(20 CHAR).
But it is showing up as 80 IN dba_tab_columns.data_length ? Why is that ?

SQL> desc STRP_SLS.CRTN_MONTH_DTL
Name                    Type               Nullable Default Comments 
----------------------- ------------------ -------- ------- -------- 
MONTH_ID                NUMBER(6)          Y                         
CLIENT_ID               VARCHAR2(100 CHAR) Y                         
MGMT_CTRY_ID            VARCHAR2(4 CHAR)   Y                         
PRODUCT_SEGMENT_ID      VARCHAR2(20 CHAR)  Y    -----------> column in question                     
RWA_AMOUNT              NUMBER(20,5)       Y                         
TOTAL_REVENUE_AMOUNT    NUMBER(20,5)       Y   



SQL> col data_type format a25
SQL> col column_name format a25
SQL> set lines 200
SQL> select column_name, Data_type, data_length, char_length
  2   from dba_tab_columns WHERE TABLE_NAME = 'CRTN_MONTH_DTL'
  3  and column_name = 'PRODUCT_SEGMENT_ID' and OWNER = 'STRP_SLS';

COLUMN_NAME               DATA_TYPE                 DATA_LENGTH CHAR_LENGTH
------------------------- ------------------------- ----------- -----------
PRODUCT_SEGMENT_ID        VARCHAR2                           80          20

I extracted the CREATE TABLE ddl for this table . It confirms that PRODUCT_SEGMENT_ID is created with VARCHAR2(20 CHAR)

create table STRP_SLS.CRTN_MONTH_DTL
(
month_id                NUMBER(6),
client_id               VARCHAR2(100 CHAR),
mgmt_ctry_id            VARCHAR2(4 CHAR),
PRODUCT_SEGMENT_ID      VARCHAR2(20 CHAR), -----------> column in question
rwa_amount              NUMBER(20,5),
total_revenue_amount    NUMBER(20,5),
.
.
.