Data Type
Limits (11g):
|
Datatypes
|
Limit
|
Comments
|
|
BFILE
|
Maximum size: 4 GB
Maximum size of a file name: 255 characters
Maximum size of a directory name: 30 characters
Maximum number of open BFILEs: see Comments
|
The maximum number of BFILEs is limited by the value of the SESSION_MAX_OPEN_FILES initialization
parameter, which is itself limited by the maximum number of open files the
operating system will allow.
|
|
BLOB
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Maximum size: (4 GB - 1) * DB_BLOCK_SIZE initialization parameter (8 TB to 128 TB)
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The number of LOB columns per table is limited only by the maximum number
of columns per table (that is, 1000Foot 1 ).
|
|
CHAR
|
Maximum
size: 2000 bytes
|
None
|
|
CHAR VARYING
|
Maximum
size: 4000 bytes
|
None
|
|
CLOB
|
Maximum size: (4 GB - 1) * DB_BLOCK_SIZE initialization parameter (8 TB to 128 TB)
|
The number of LOB columns per table is limited only by the maximum number
of columns per table (that is, 1000Footref 1).
|
|
Literals (characters or numbers in SQL or PL/SQL)
|
Maximum
size: 4000 characters
|
None
|
|
LONG
|
Maximum
size: 2 GB - 1
|
Only one LONG column
is allowed per table.
|
|
NCHAR
|
Maximum
size: 2000 bytes
|
None
|
|
NCHAR VARYING
|
Maximum
size: 4000 bytes
|
None
|
|
NCLOB
|
Maximum size: (4 GB - 1) * DB_BLOCK_SIZE initialization parameter (8 TB to 128 TB)
|
The number of LOB columns per table is limited only by the maximum number
of columns per table (that is, 1000Footref 1).
|
|
NUMBER
|
999...(38 9's) x10125 maximum value
-999...(38 9's) x10125 minimum value
|
Can be represented to full 38-digit precision (the mantissa)
Can be represented to full 38-digit precision (the mantissa)
|
|
Precision
|
38
significant digits
|
None
|
|
RAW
|
Maximum
size: 2000 bytes
|
None
|
|
VARCHAR
|
Maximum
size: 4000 bytes
|
None
|
|
VARCHAR2
|
Maximum
size: 4000 bytes
|
None
|
Footnote 1 The absolute maximum number of columns in a table is 1000. However, when you create an object table (or a relational table with columns of object, nested table, varray, or REF type), Oracle maps the columns of the user-defined types to relational columns, creating in effect hidden columns that count toward the 1000-column limit. Source: Oracle |