A.3 Logical Database Limits
This table describes limit types and limit values for logical database items.
| Item | Type of Limit | Limit Value |
|---|---|---|
|
Columns |
Maximum per table |
1000 |
|
Columns |
Maximum per index (or clustered index) |
32 |
|
Columns |
Maximum per bitmapped index |
30 |
|
Constraints |
Maximum per column |
Unlimited |
|
Constraints |
Maximum per database |
4,294,967,293 |
|
Database users |
Maximum per database |
4,294,967,293 |
|
Dictionary-managed database objects |
Maximum per database |
4,254,950,911 - overhead |
|
Indexes |
Maximum per table |
Unlimited |
|
Indexes |
Total size of indexed column |
75% of the database block size minus some overhead |
|
Partitions |
Maximum length of linear partitioning key |
4 KB - overhead |
|
Partitions |
Maximum number of columns in partition key |
16 columns |
|
Partitions |
Maximum number of partitions allowed per table or index |
1024K - 1 |
|
Rows |
Maximum number per table |
Unlimited |
|
Stored Packages |
Maximum size |
Approximately See Also: Oracle Database PL/SQL Language Reference for details |
|
Subpartitions |
Maximum number of subpartitions in a composite partitioned table |
1024K - 1 |
|
Subqueries |
Maximum levels of subqueries in a SQL statement |
Unlimited in the
|
|
System Change Numbers (SCNs) |
Maximum |
281,474,976,710,656, which is 281 trillion SCNs |
|
Tables |
Maximum per clustered table |
32 tables |
|
Tables |
Maximum per database |
Unlimited Oracle does not define a limit on the number of tables per database. However, tables are subject to the limit on the maximum number of dictionary-managed database objects allowed per database. See the entry for "Dictionary-managed database objects" in this table. |
|
Trigger Cascade Limit |
Maximum value |
Operating system-dependent, typically |
|
Users and Roles |
Maximum |
2,147,483,638 |
Note:
The limit on how long a SQL statement can be depends on many factors, including database configuration, disk space, and memory
Note:
When an object instance exists in memory, there is no fixed limit on the number of attributes in the object. But the maximum total amount of memory consumed by an object instance is 4 GB. When an object instance is inserted into a table, the attributes are exploded into separate columns in the table, and the Oracle 1000-column limit applies.