VECTOR_ SORT
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The VECTOR_
function sorts the elements in the vector expression and returns the sorted vector.
Syntax
VECTOR_SORT(vector_expression [,'ASC'|'DESC'])
Arguments
-
vector_
: An expression that evaluates to a vector.expression Vectors can be stored in SingleStore using the native VECTOR
type (Vector Type) or theBLOB
type (BLOB Types).SingleStore recommends using the VECTOR
type when possible.
-
ASC
orDESC
: 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_
Using VECTOR_ ELEMENTS_ SORT with the VECTOR Type
The examples below show two uses of VECTOR_
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 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.
SELECT id, VECTOR_SORT(vec, 'ASC')FROM vectorsORDER 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_
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_
table in descending order.
SELECT id, VECTOR_SORT(vec, 'DESC')FROM vectors_i16ORDER 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_
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.vec
and type BLOB
, will store the vectors.BLOB
s, hence the column of type BLOB
named vec
.
Then use the JSON_
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_
table in ascending order and uses JSON_
to see the results in JSON format.
SELECT id, JSON_ARRAY_UNPACK(VECTOR_SORT(vec)) AS vector_sortFROM vectors_bORDER 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_
.
JSON_
was used here to output the vectors in readable format because VECTOR_
returns a BLOB
when its second argument is a BLOB
.
The following query sorts the vectors in the vectors_
table and uses HEX
to view the results in hexadecimal format.
SELECT id, HEX(VECTOR_SORT(vec)) as vector_sortFROM vectors_bORDER 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
).
You can specify the datatype of the vector elements to be used in the operation by adding a suffix to the function._
.
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 |
---|---|
|
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 2 - BLOBs with 16-bit Integers
Below is an example of using JSON_
and VECTOR_
with 16-bit signed integers.
First create a table of vectors stored as 16-bit integers._
suffix on JSON_
.
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_
table in ascending order.
SELECT id, JSON_ARRAY_UNPACK_I16(VECTOR_SORT_I16(vec)) AS vector_sortFROM vectors_b_iORDER 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_
.BLOB
s.BLOB
containing packed numbers in little-endian byte order.BLOB
s 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