Sign inTry Free

VECTOR_SORT

On this page

The VECTOR_SORT function sorts the elements in the vector expression and returns the sorted vector.

Syntax

VECTOR_SORT(vector_expression [,'ASC'|'DESC'])

Arguments

  • vector_expression: An expression that evaluates to a vector. Vectors can be stored in SingleStore using the native VECTOR type (Vector Type) or the BLOB type (BLOB Types). SingleStore recommends using the VECTOR type when possible.

  • ASC or DESC: The sort order in which the vector will be returned. ASC means ascending order. DESC means descending order. ASC is the default.

Return Type

The function returns the type of the first argument (the vector_expression).

Output Format for Examples

Vectors may be output in JSON or binary format. Use JSON format for examples and for output readability. For production, use the default binary for efficiency.

To get JSON output which will match the examples, use the following command to output vectors in JSON.

SET vector_type_project_format = JSON;

Use the following command to set the output format back to binary.

SET vector_type_project_format = BINARY;

Using VECTOR_ELEMENTS_SORT with the VECTOR Type

The examples below show two uses of VECTOR_ELEMENTS_SORT with different types of VECTOR arguments.

Example 1 - Vector with F32 Element Type

First create a table of vectors of length 4 using the VECTOR type and insert data into that table.

CREATE TABLE vectors (id int, vec VECTOR(4) not null);


INSERT INTO vectors VALUES (1, '[0.45, 0.55, 0.495, 0.5]');
INSERT INTO vectors VALUES (2, '[0.1, 0.8, 0.2, 0.555]');
INSERT INTO vectors VALUES (3, '[-0.5, -0.03, -0.1, 0.86]');
INSERT INTO vectors VALUES (4, '[0.5, 0.3, 0.807, 0.1]');

Note

The default element type for Vector Type is 32-bit floating point (F32). The Vector Type supports other element types, including integer types, as described in the Vector Type documentation.

The following SQL sorts each of those vectors in ascending (ASC) order.

Click the Playground icon to the right of the SQL listing to try this query. Also, try experimenting and writing your own query.

SET vector_type_project_format = JSON;  /* to make vector output readable */


SELECT id, VECTOR_SORT(vec, 'ASC')
FROM vectors
ORDER BY id;
+------+---------------------------------------------------+
| id   | VECTOR_SORT(vec, 'ASC')                           |
+------+---------------------------------------------------+
|    1 | [0.449999988,0.495000005,0.5,0.550000012]         |
|    2 | [0.100000001,0.200000003,0.555000007,0.800000012] |
|    3 | [-0.5,-0.100000001,-0.0299999993,0.860000014]     |
|    4 | [0.100000001,0.300000012,0.5,0.806999981]         |
+------+---------------------------------------------------+

Example 2 - Vector with I16 Element Type

This example shows how to use VECTOR_SORT with a VECTOR with an elementType of 16-bit integer (I16).

CREATE TABLE vectors_i16(id INT, vec VECTOR(3, I16));


INSERT INTO vectors_i16 VALUES(1, '[1, 2, 3]');
INSERT INTO vectors_i16 VALUES(2, '[4, 5, 6]');
INSERT INTO vectors_i16 VALUES(3, '[1, 4, 8]');

The following SQL sorts each of the vectors in the vectors_i16 table in descending order.

SET vector_type_project_format = JSON;  /* to make vector output readable */


SELECT id, VECTOR_SORT(vec, 'DESC')
FROM vectors_i16
ORDER BY id;
+------+--------------------------+
| id   | VECTOR_SORT(vec, 'DESC') |
+------+--------------------------+
|    1 | [3,2,1]                  |
|    2 | [6,5,4]                  |
|    3 | [8,4,1]                  |
+------+--------------------------+

Using VECTOR_SORT with Vectors as BLOBs

The following example shows the use of VECTOR_SORT to sort the elements of a vector stored as a BLOB.

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 |
+------+----------------------------------+

Using Suffixes for Other Element Types with BLOBs

The default element type for vector storage and processing is 32-bit floating point (F32). However, other element types are supported.

You can specify the datatype of the vector elements to be used in the operation by adding a suffix to the function. All operations are done using the specified datatype. Omitting the suffix from the function is equivalent to suffixing it with _F32.

When using a suffix, the return type will be the type of the suffix.

Note

The functions with suffixes do not work with the VECTOR type.

The following table lists the suffixes and their data type.

Suffix

Data Type

_I8

8-bit signed integer

_I16

16-bit signed integer

_I32

32-bit signed integer

_I64

64-bit signed integer

_F32

32-bit floating-point number (IEEE standard format)

_F64

64-bit floating-point number (IEEE standard format)

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] |
+------+-------------+

Note

Be sure that the suffixes you use to pack the vector data match the suffixes you use to unpack the data and the suffixes you use on functions to process that data.

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).

Related Topics

Last modified: May 30, 2024

Was this article helpful?

On this page

Was this article helpful?