The use of LONG
values is subject to these restrictions:
- A table can contain only one LONG column.
- You cannot create an object type with a LONG attribute.
- LONG columns cannot appear in WHERE clauses or in integrity
constraints (except that they can appear in NULL and NOT NULL constraints).
- LONG columns cannot be indexed.
- LONG data cannot be specified in regular expressions.
- A stored function cannot return a LONG value.
- You can declare a variable or argument of a PL/SQL program unit
using the LONG data type. However, you cannot then call the program unit
from SQL.
- Within a single SQL statement, all LONG columns, updated tables,
and locked tables must be located on the same database.
- LONG and LONG RAW columns cannot be used in distributed SQL
statements and cannot be replicated.
- If a table has both LONG and LOB columns, then you cannot bind more
than 4000 bytes of data to both the LONG and LOB columns in the same SQL
statement. However, you can bind more than 4000 bytes of data to either
the LONG or the LOB column.
In addition, LONG
columns cannot appear in these parts of SQL statements:
- GROUP BY clauses, ORDER BY clauses, or CONNECT BY clauses or with
the DISTINCT operator in SELECT statements
- The UNIQUE operator of a SELECT statement
- The column list of a CREATE CLUSTER statement
- The CLUSTER clause of a CREATE MATERIALIZED VIEW statement
- SQL built-in functions, expressions, or conditions
- SELECT lists of queries containing GROUP BY clauses
- SELECT lists of subqueries or queries combined by the UNION,
INTERSECT, or MINUS set operators
- SELECT lists of CREATE TABLE ... AS SELECT statements
- ALTER TABLE ... MOVE statements
- SELECT lists in subqueries in INSERT statements
