VECTOR_SUM
Returns a vector, which is a sum of all vectors in a column.
It is an aggregate function.
Syntax
VECTOR_SUM(vector_expression)
Arguments
vector_expression
: An expression that evaluates to a vector. The vector must be encoded as a blob containing packed 8, 16 or 32 bit integer numbers; 32 or 64 bit floating-point numbers; single-precision; or double-precision floating-point numbers in little-endian byte order.
Return Type
A blob containing packed single-precision floating-point numbers in little-endian byte order.
Remarks
You can specify the datatype of the vector elements in which this operation is performed on the vector by adding a suffix to the function. Omitting the suffix from the function is equivalent to suffixing it with _F32
. All operations are done using the specified datatype. The following table lists the suffixes and their datatype.
Suffix | Datatype |
---|---|
| 8-bit signed integer |
| 16-bit signed integer |
| 32-bit signed integer |
| 64-bit signed integer |
| 32-bit floating-point number (IEEE standard format) |
| 64-bit floating-point number (IEEE standard format) |
Example
The following examples use the JSON_ARRAY_UNPACK()
function to view the output in JSON format.
Adding Two Vectors
The following example uses the t
table:
CREATE TABLE v_t (x BLOB, y BLOB); INSERT INTO v_t VALUES (JSON_ARRAY_PACK('[12.1, 6.4]'), JSON_ARRAY_PACK('[8.6,9.2]')); INSERT INTO v_t VALUES (JSON_ARRAY_PACK('[5.2, 11.7]'), JSON_ARRAY_PACK('[4.6,7.3]'));
This example sums the vector blobs for each column using the VECTOR_SUM()
aggregate function:
SELECT JSON_ARRAY_UNPACK(VECTOR_SUM(x)), JSON_ARRAY_UNPACK(VECTOR_SUM(y)) FROM v_t; **** +----------------------------------+----------------------------------+ | JSON_ARRAY_UNPACK(VECTOR_SUM(x)) | JSON_ARRAY_UNPACK(VECTOR_SUM(y)) | +----------------------------------+----------------------------------+ | [17.2999992,18.1000004] | [13.2000008,16.5] | +----------------------------------+----------------------------------+ 1 row in set (0.01 sec)
Typecasting the Datatype Using Suffixes
To perform this operation on vectors specified in a format other than the default 32-bit floating point number, specify a suffix with the VECTOR_SUM()
function.
-- _i8 suffix SELECT JSON_ARRAY_UNPACK(VECTOR_SUM_i8(x)), JSON_ARRAY_UNPACK(VECTOR_SUM_i8(y)) FROM v_t; **** +-------------------------------------+-------------------------------------+ | JSON_ARRAY_UNPACK(VECTOR_SUM_i8(x)) | JSON_ARRAY_UNPACK(VECTOR_SUM_i8(y)) | +-------------------------------------+-------------------------------------+ | [-8.52219055e-38,-2.49785375e-38] | [-5.75992243e-38,-9.28640548e-38] | +-------------------------------------+-------------------------------------+ 1 row in set (0.01 sec)
-- _i16 suffix SELECT JSON_ARRAY_UNPACK(VECTOR_SUM_i16(x)), JSON_ARRAY_UNPACK(VECTOR_SUM_i16(y)) FROM v_t; **** +--------------------------------------+--------------------------------------+ | JSON_ARRAY_UNPACK(VECTOR_SUM_i16(x)) | JSON_ARRAY_UNPACK(VECTOR_SUM_i16(y)) | +--------------------------------------+--------------------------------------+ | [-8.48559984e-38,-9.91823359e-38] | [-5.75992243e-38,-9.28640548e-38] | +--------------------------------------+--------------------------------------+ 1 row in set (0.03 sec)
-- _i32 suffix SELECT JSON_ARRAY_UNPACK(VECTOR_SUM_i32(x)), JSON_ARRAY_UNPACK(VECTOR_SUM_i32(y)) FROM v_t; **** +--------------------------------------+--------------------------------------+ | JSON_ARRAY_UNPACK(VECTOR_SUM_i32(x)) | JSON_ARRAY_UNPACK(VECTOR_SUM_i32(y)) | +--------------------------------------+--------------------------------------+ | [-8.52233404e-38,-9.99170198e-38] | [-5.75992243e-38,-9.28640548e-38] | +--------------------------------------+--------------------------------------+ 1 row in set (0.02 sec)
-- _i64 suffix SELECT JSON_ARRAY_UNPACK(VECTOR_SUM_i64(x)), JSON_ARRAY_UNPACK(VECTOR_SUM_i64(y)) FROM v_t; **** +--------------------------------------+--------------------------------------+ | JSON_ARRAY_UNPACK(VECTOR_SUM_i64(x)) | JSON_ARRAY_UNPACK(VECTOR_SUM_i64(y)) | +--------------------------------------+--------------------------------------+ | [-8.52233404e-38,-9.99170198e-38] | [-5.75992243e-38,-9.28640548e-38] | +--------------------------------------+--------------------------------------+ 1 row in set (0.03 sec)
-- _f64 suffix SELECT JSON_ARRAY_UNPACK(VECTOR_SUM_f64(x)), JSON_ARRAY_UNPACK(VECTOR_SUM_f64(y)) FROM v_t; **** +--------------------------------------+--------------------------------------+ | JSON_ARRAY_UNPACK(VECTOR_SUM_f64(x)) | JSON_ARRAY_UNPACK(VECTOR_SUM_f64(y)) | +--------------------------------------+--------------------------------------+ | [-4.75446394e+16,11.7140617] | [-1.8777817e-33,9.39999962] | +--------------------------------------+--------------------------------------+ 1 row in set (0.03 sec)