OpenSQL Statements
OpenSQL statements used in Ingres are subject to the following restrictions when used in other Enterprise Access databases:
• The DBMSINFO parameter must be a literal.
• DBMSINFO functions may be used inside other scalars that allow nesting for parameters that are not required to be literals.
• DBMSINFO may only be used as the inner most scalar. Nesting DBMSINFO is not recommended.
• Maximum tuple size:
– Microsoft SQL: 8060 bytes
• Unlike OpenSQL, all cursors opened through the gateway are opened READONLY unless explicitly opened FOR UPDATE. That is, if UPDATE WHERE CURRENT or DELETE WHERE CURRENT is used, the cursor must explicitly be opened FOR UPDATE.
• Unlike OpenSQL, in Enterprise Access the column list in the FOR UPDATE clause is optional. However, a column list in a FOR UPDATE clause is recommended for portability.