This appendix contains the following sections:
With a few exceptions, the gateway provides full support for Oracle DELETE, INSERT, SELECT, and UPDATE statements.
The gateway does not support Oracle data definition language (DDL) statements. No form of the Oracle ALTER, CREATE, DROP, GRANT, or TRUNCATE statements can be used. Instead, use the pass-through feature of the gateway if you need to use DDL statements against the Teradata database.
See Also: Oracle SQL Reference for a detailed descriptions of keywords, parameters, and options. |
The DELETE statement is fully supported. However, only Oracle functions supported by Teradata can be used.
The INSERT statement is fully supported. However, only Oracle functions supported by Teradata can be used.
The SELECT statement is fully supported, with these exceptions:
CONNECT BY condition
NOWAIT
START WITH condition
WHERE CURRENT OF
All functions are evaluated by the Teradata database after the gateway has converted them to Teradata SQL.
Oracle SQL functions with no equivalent function in Teradata are not supported in DELETE, INSERT, or UPDATE statements, but are evaluated by the Oracle database server if the statement is a SELECT statement. That is, the Oracle database server performs post-processing of SELECT statements sent to the gateway.
If an unsupported function is used in a DELETE, INSERT, or UPDATE, statement, the following Oracle error occurs:
ORA-02070: database db_link_name does not support function in this context
The gateway translates the following Oracle database server functions in SQL statements to their equivalent Teradata functions:
Oracle | Teradata |
---|---|
= | = |
> | > |
< | < |
>= | >= |
<= | <= |
<>, !=, ^= | <>, != |
IS NOT NULL | IS NOT NULL |
IS NULL | IS NULL |
Oracle | Teradata |
---|---|
|| | CONCAT |
INSTR | LOCATE |
LENGTH | LENGTH |
SUBSTR (second argument cannot be a negative number) | SUBSTRING |
UPPER | UCASE |