GROUP BY clause 

Maximum length 

The GROUP BY expression and all of the nondistinct aggregates functions (e.g., SUM, AVG) must fit within a single database block. 

Indexes 

Maximum per table 

Unlimited 

total size of indexed column 

40% of the database block size minus some overhead. 

Columns 

Per table 

1000 columns maximum 

Per index (or clustered index) 

32 columns maximum 

Per bitmapped index 

30 columns maximum 

Constraints 

Maximum per column 

Unlimited 

Nested Queries 

Maximum number 

255  

Partitions 

Maximum length of linear partitioning key 

4KB - overhead 

Maximum number of columns in partition key 

16 columns 

Maximum number of partitions allowed per table or index 

64K-1 partitions 

Rollback Segments 

Maximum number per database 

No limit; limited within a session by the MAX_ROLLBACK_SEGMENTS initialization parameter 

Rows 

Maximum number per table 

Unlimited 

SQL Statement Length 

Maximum length of statements 

64K maximum; particular tools may impose lower limits. 

Stored Packages 

Maximum size 

PL/SQL and Developer/2000 may have limits on the size of stored procedures they can call. The limits typically range from 2000 to 3000 lines of code.

See Also: Your PL/SQL or Developer/2000 documentation for details.  

Trigger Cascade Limit 

Maximum value 

Operating system dependent, typically 32. 

Users and Roles 

Maximum 

2,147,483,638 

Tables 

Maximum per clustered table 

32 tables 

Maximum per database 

Unlimited