VECTOR_MUL
Multiplies two vector blobs and returns a single vector blob.
It is a scalar function.
Syntax
VECTOR_MUL(vector_expression, vector_expression)
Arguments
vector_expression: An expression that evaluates to a vector. The vector must be encoded as a blob containing packed 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
A vector can be of any length, but the input blob length must be divisible by the packed vector element size (1, 2, 4 or 8 bytes, depending on the vector element).
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) |
Examples
The following queries use the JSON_ARRAY_UNPACK() function to view the output in JSON format.
Multiplying Two Vectors
The following example multiplies two vectors using the VECTOR_MUL function:
SELECT JSON_ARRAY_UNPACK(VECTOR_MUL(JSON_ARRAY_PACK('[12.1,2.2]'),JSON_ARRAY_PACK('[8.3,4.6]'))) AS "Result";
****
+-------------------------+
| Result |
+-------------------------+
| [100.430008,10.1199999] |
+-------------------------+
You can also view the vector blob in hexadecimal format using the HEX() function.
SELECT HEX(VECTOR_MUL(JSON_ARRAY_PACK('[12.1,2.2]'),JSON_ARRAY_PACK('[8.3,4.6]'))) AS "Result";
****
+------------------+
| Result |
+------------------+
| 2ADCC84285EB2141 |
+------------------+Typecasting the Data 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_MUL() function. For example,
SELECT JSON_ARRAY_UNPACK_I16(VECTOR_MUL_I16(JSON_ARRAY_PACK_I16('[6,2]'),JSON_ARRAY_PACK_I16('[8,4]'))) AS "Result";
****
+--------+
| Result |
+--------+
| [48,8] |
+--------+