| 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 |
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, 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. For details on how Oracle calculates the total number of columns in such a table, refer to Oracle Database Administrator's Guide.
See Also:
Oracle Database SQL Language Reference for information on the rules and limitations governing the use of datatypes and naming database objects