Aggregate Function Parameter Syntax Elements - Analytics Database - Teradata Vantage

SQL External Routine Programming
Deployment
VantageCloud
VantageCore
Edition
Enterprise
IntelliFlex
VMware
Product
Analytics Database
Teradata Vantage
Release Number
17.20
Published
June 2022
ft:locale
en-US
ft:lastEdition
2025-03-30
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qnu1472247494689
lifecycle
latest
Product Category
Teradata Vantage™
function_name
Pointer to a C string whose value is the function name in the CREATE FUNCTION definition.
The function can use this name to build error messages.
aggregation_phase
Current aggregation phrase, which determines how the aggregate function processes the input data.
The aggregation phrase definition is:
typedef enum {
  AGR_INIT    = 1,
  AGR_DETAIL  = 2,
  AGR_COMBINE = 3,
  AGR_FINAL   = 4,
  AGR_NODATA  = 5
} FNC_Phase;
aggregation_phase Value How Function Processes Input Data
AGR_INIT Function allocates and initializes intermediate storage for accumulating summary information.
AGR_DETAIL Function accumulates input data into intermediate storage area for specified group.
AGR_COMBINE Function combines intermediate storage areas for each group being aggregated.
AGR_FINAL Function produces final aggregate result for group.
AGR_NODATA Function produces result for null aggregate set.
function_context
Pointer to the function context structure, the intermediate aggregate storage area for groups on which the aggregate function operates.
The function context structure definition is:
typedef struct FNC_Context_t {
  int         version;
  FNC_flags_t flags;
  void        *interim1;
  int         intrm1_length;
  void        *interim2;
  int         intrm2_length;
  long        group_count;
  long        window_size;
  long        pre_window;
  long        post_window;
} FNC_Context_t;
FNC_Context_t Member Description
version Version of context structure. Current version is 1.
interim1 Pointer to aggregate storage area that saves intermediate results.
intrm1_length Length of interim1.
interim2 Pointer to intermediate storage area to combine with interim1 storage area when value of aggregation_phase is AGR_COMBINE.
intrm2_length Length of interim2.
FNC_Context_t members not defined are reserved for future use.
input_parameter_specification
[Optional] Type and name of an input parameter in the CREATE FUNCTION definition. Each input parameter in the definition must have a corresponding input_parameter_specification. The maximum number of input parameters is 128.
The type is the C type in sqltypes_td.h that corresponds to the SQL data type of input_parameter.
result
Pointer to a data area big enough to hold the result that the function returns, as defined by the RETURNS clause in the corresponding CREATE FUNCTION statement.
indicator_parameter_specification
[Optional] Indicator parameter corresponding to an input parameter. Each input_parameter_specification must have a corresponding indicator_parameter_specification. The input parameters and indicator parameters must be in the same order.
If the value of indicator_parameter is -1, the value of the corresponding input_parameter is null.
If the value of indicator_parameter is 0, the value of the corresponding input_parameter is a non-null value.
indicator_result
Result indicator parameter corresponding to the result.
sqlstate
Pointer to a six-character C string that indicates the SQLSTATE value—success, exception, or warning. The first five characters are ASCII and the sixth is the C null character. The string is initialized to '00000', which indicates success.
See Returning SQLSTATE Values.
m
Number of characters in the function name in the CREATE FUNCTION definition. The ANSI SQL standard defines the maximum value for m as 128. Vantage allows a maximum of 30 characters for a function name.
specific_function_name
Pointer to a C string whose value is the name of the external function being invoked.
If the CREATE FUNCTION statement includes the SPECIFIC clause, specific_function_name is the name in the SPECIFIC clause; otherwise, specific_function_name is the same as function_name.
The function can use this name to build error messages.
l
Number of characters in the name of the external function. The ANSI SQL standard defines the maximum value for m as 128. Vantage allows a maximum of 30 characters for a function name.
error_message
Pointer to a C string whose value is the the error message text.
p
Number of characters in the error message text. The maximum value is 256.
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