What are the maximum length of a table name and column name in Oracle?
The maximum length of the table and column name is 128 bytes or 128 characters. This limit is for using sybase database users. I verified this answer thoroughly, so that I have posted this answer confidently.
The schema object naming rules may also be of some use:
http://download.oracle.com/docs/cd/B19306_01/server.102/b14200/sql_elements008.htm#sthref723
Notice the data-type and size
>describe all_tab_columns
VIEW all_tab_columns
Name Null? Type
----------------------------------------- -------- ----------------------------
OWNER NOT NULL VARCHAR2(30)
TABLE_NAME NOT NULL VARCHAR2(30)
COLUMN_NAME NOT NULL VARCHAR2(30)
DATA_TYPE VARCHAR2(106)
DATA_TYPE_MOD VARCHAR2(3)
DATA_TYPE_OWNER VARCHAR2(30)
DATA_LENGTH NOT NULL NUMBER
DATA_PRECISION NUMBER
DATA_SCALE NUMBER
NULLABLE VARCHAR2(1)
COLUMN_ID NUMBER
DEFAULT_LENGTH NUMBER
DATA_DEFAULT LONG
NUM_DISTINCT NUMBER
LOW_VALUE RAW(32)
HIGH_VALUE RAW(32)
DENSITY NUMBER
NUM_NULLS NUMBER
NUM_BUCKETS NUMBER
LAST_ANALYZED DATE
SAMPLE_SIZE NUMBER
CHARACTER_SET_NAME VARCHAR2(44)
CHAR_COL_DECL_LENGTH NUMBER
GLOBAL_STATS VARCHAR2(3)
USER_STATS VARCHAR2(3)
AVG_COL_LEN NUMBER
CHAR_LENGTH NUMBER
CHAR_USED VARCHAR2(1)
V80_FMT_IMAGE VARCHAR2(3)
DATA_UPGRADED VARCHAR2(3)
HISTOGRAM VARCHAR2(15)
Oracle database object names maximum length is 30 bytes.
Object Name Rules: http://docs.oracle.com/database/121/SQLRF/sql_elements008.htm
30 char (bytes, really, as has been stated).
But do not trust me; try this for yourself:
SQL> create table I23456789012345678901234567890 (my_id number);
Table created.
SQL> create table I234567890123456789012345678901(my_id number);
ERROR at line 1:
ORA-00972: identifier is too long
Updated: as stated above, in Oracle 12.2 and later, the maximum object name length is now 128 bytes.
On Oracle 12.2
, you can use built-in constant, ORA_MAX_NAME_LEN
,
set to 128 bytes (as per 12.2)
Prior to Oracle 12.1
max size was 30 bytes.