EXTFNAPIV4_DESCRIBE_COL_IS_CONSTANT (Get)

Data Type

a_sql_byte

Description

True, if the column is constant for the lifetime of the statement. This property is valid only for input table arguments.

Usage

If a UDF gets this property, the return value is 1 if the column is constant for the lifetime of the statement and 0 otherwise. Input table columns are constant, if the column in the select list for the input table is a constant expression or NULL.

Returns

On success, returns the sizeof(a_sql_byte), if the value was returned, or:

• EXTFNAPIV4_DESCRIBE_NOT_AVAILABLE – the attribute is not available to get. Returned, if the column is not involved in the query.

On failure, returns one of the generic describe_column errors, or:

• EXTFNAPIV4_DESCRIBE_BUFFER_SIZE_MISMATCH – get error returned, if the describe buffer is not the size of a_sql_byte.
• EXTFNAPIV4_DESCRIBE_INVALID_STATE – get error returned, if the state is not greater than Initial.
• EXTFNAPIV4_DESCRIBE_INVALID_PARAMETER – get error returned, if the specified argument is not an input table.

Query Processing States

Valid in:

• Annotation state
• Query Optimization state
• Plan Building state
• Execution state