VECTOR_SORT

Example 1 - BLOB Argument

Create a table with a column of type BLOB to store the vectors. The second column in this table, with column name vec and type BLOB, will store the vectors. This example demonstrates storing vector data using BLOBs, hence the column of type BLOB named vec.

Then use the JSON_ARRAY_PACK built-in function to easily insert properly formatted vectors.

CREATE TABLE vectors_b (id int, vec BLOB not null);

INSERT INTO vectors_b VALUES (1, JSON_ARRAY_PACK('[0.1, 0.8, 0.2, 0.555]')); 
INSERT INTO vectors_b VALUES (2, JSON_ARRAY_PACK('[0.45, 0.55, 0.495, 0.5]'));

The following query sorts the vectors in the vectors_b table in ascending order and uses JSON_ARRAY_UNPACK to see the results in JSON format.

SELECT id, JSON_ARRAY_UNPACK(VECTOR_SORT(vec)) AS vector_sort
FROM vectors_b
ORDER BY id;

+------+---------------------------------------------------+
| id   | vector_sort                                       |
+------+---------------------------------------------------+
|    1 | [0.100000001,0.200000003,0.555000007,0.800000012] |
|    2 | [0.449999988,0.495000005,0.5,0.550000012]         |
+------+---------------------------------------------------+

The results are sorted in ascending order as that is the default sort order for VECTOR_SORT.

JSON_ARRAY_UNPACK was used here to output the vectors in readable format because VECTOR_SORT returns a BLOB when its second argument is a BLOB.

The following query sorts the vectors in the vectors_b table and uses HEX to view the results in hexadecimal format.

SELECT id, HEX(VECTOR_SORT(vec)) as vector_sort
FROM vectors_b
ORDER BY id;

+------+----------------------------------+
| id   | vector_sort                      |
+------+----------------------------------+
|    1 | CDCCCC3DCDCC4C3E7B140E3FCDCC4C3F |
|    2 | 6666E63EA470FD3E0000003FCDCC0C3F |
+------+----------------------------------+

Example 2 - BLOBs with 16-bit Integers

Below is an example of using JSON_ARRAY_PACK and VECTOR_SORT with 16-bit signed integers.

First create a table of vectors stored as 16-bit integers. Note the use of the _I16 suffix on JSON_ARRAY_PACK.

CREATE TABLE vectors_b_i (id int, vec BLOB not null);

INSERT INTO vectors_b_i VALUES (1, JSON_ARRAY_PACK_I16('[1, 3, 2, 5]')); 
INSERT INTO vectors_b_i VALUES(2, JSON_ARRAY_PACK_I16('[23, 4, 1, 8]'));

The following query sorts the vectors in the vectors_b_i table in ascending order.

SELECT id, JSON_ARRAY_UNPACK_I16(VECTOR_SORT_I16(vec)) AS vector_sort
FROM vectors_b_i
ORDER BY id;

+------+-------------+
| id   | vector_sort |
+------+-------------+
|    1 | [1,4,8,16]  |
|    2 | [2,5,10,15] |
+------+-------------+

Formatting Binary Vector Data for BLOBs

When using the BLOB type for vector operations, vector data can be formatted using JSON_ARRAY_PACK. If your vector data is already in a packed binary format, you can load that data into the BLOBs. The data must be encoded as a BLOB containing packed numbers in little-endian byte order. Vectors stored as BLOBs can be of any length; however, the input blob length must be divisible by the size of the packed vector elements (1, 2, 4 , or 8 bytes, depending on the vector element).