2.12.13 Vector Functions

The following table shows supported vector functions. These are not supported with dictionary-encoded columns. These were introduced in MySQL 9.0.0.

Table 2.13 Vector Functions

Name	Description
DISTANCE()	Calculates the distance between two vectors with the specified method
VECTOR_TO_STRING()	Get the string representation of a VECTOR column, given its value as a binary string
FROM_VECTOR()	A synonym for VECTOR_TO_STRING()
TO_VECTOR()	A synonym for STRING_TO_VECTOR()
VECTOR_DIM()	Get the length of a vector, that is, the number of entries it contains
VECTOR_DISTANCE	A synonym for DISTANCE()
VECTOR_TO_STRING()	Get the string representation of a VECTOR column, given its value as a binary string

• DISTANCE(vector, vector, string)

  Calculates the distance between two vectors per the specified calculation method. It accepts the following arguments:

  • A column of VECTOR data type.

  • An input query of VECTOR data type.

  • A string that specifies the distance metric. The supported values are COSINE, DOT, and EUCLIDEAN. The argument is a string, and requires quotation marks.

  Examples:

  mysql> SELECT DISTANCE(STRING_TO_VECTOR("[1.01231, 2.0123123, 3.0123123, 4.01231231]"), STRING_TO_VECTOR("[1, 2, 3, 4]"), "COSINE");
  +-----------------------------------------------------------------------------------------------------------------------+
  | DISTANCE(STRING_TO_VECTOR("[1.01231, 2.0123123, 3.0123123, 4.01231231]"), STRING_TO_VECTOR("[1, 2, 3, 4]"), "COSINE") |
  +-----------------------------------------------------------------------------------------------------------------------+
  |                                                                                              0.0000016689300537109375 |
  +-----------------------------------------------------------------------------------------------------------------------+