Maximum length of an SQL statement |
≥ 16 KB (default 64 KB), defined by a support database parameter |
Length of a label |
32 characters |
Numeric precision |
38 digits |
Number of tables |
Unlimited |
Number of columns in each table (with KEY) |
1024 |
Number of columns in each table (without KEY) |
1023 |
Number of primary key columns in each table |
512 |
Number of columns in an index |
16 |
Number of foreign key columns per table |
16 |
Number of columns in an ORDER or GROUP clause |
128 |
Number of columns in a SELECT statement |
1023 |
Number of columns in an INSERT statement |
1024 |
Number of columns in a results table |
1023 |
Number of join tables in a SELECT statement |
254 |
Number of JOIN predicates in a search condition |
128 |
Number of triggers in each basis table |
3 |
Number of indexes for each table |
255 |
Number of referential CONSTRAINT definitions (foreign key dependencies) for each table |
Unlimited |
Number of references in each table |
Unlimited |
Number of rows in each table |
Limited by the size of a database |
Internal length of a table row |
8088 bytes |
Total of internal lengths of all key columns |
1024 bytes |
Total of internal lengths of all foreign key columns |
1024 bytes |
Total of internal lengths of all columns belonging to an index |
1024 bytes |
Internal length of a LONG column |
2 GB |
Length of the columns in an ORDER or GROUP clause |
4016 bytes |
Nested trigger levels |
Unlimited |
Nested subqueries |
127 |
Number of join conditions in a WHERE clause of a SELECT statement |
128 |
Number of correlated columns in an SQL statement |
64 |
Number of correlated tables in an SQL statement |
16 |
Number of parameters in an SQL statement |
2000 |
See also:
Concepts of the Database System, Technical Restrictions