VECTOR_SUB
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The VECTOR_
function subtracts the second vector from the first vector and returns a vector which is the result of that subtraction.
Syntax
VECTOR_SUB(vector_expression, vector_expression)
Arguments

vector_
: An expression that evaluates to a vector.expression Vectors can be stored in SingleStore using the BLOB
type (BLOB Types).
Return Type
If both arguments are BLOB
s, then the return type will be by default a BLOB
that contains a vector encoded as 32bit floating point numbers (F32
).BLOB
that contains a vector encoded using the type of the suffix.
See Using Suffixes for Other Element Types with BLOBs for information on using suffixes with vectors encoded as BLOB
s.
Using VECTOR_SUB with Vectors as BLOBs
The following examples and descriptions show the use of VECTOR_
with arguments that are both vectors stored as BLOB
s.
Example 1  BLOB Arguments
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_
builtin 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 subtracts the vector '[0.
from the vectors in the vectors_
table and uses HEX
to view the results in hexadecimal format.
SET @qv = JSON_ARRAY_PACK('[0.1,0.1,0.1,0.1]');SELECT id, HEX(VECTOR_SUB(vec, @qv)) as vector_subFROM vectors_bORDER BY id;
+++
 id  vector_sub 
+++
 1  000000003333333FCDCCCC3DC3F5E83E 
 2  3333B33E6766E63E713DCA3ECDCCCC3E 
+++
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 littleendian 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: April 8, 2024