TO_VECTOR

TO_VECTOR is a constructor that takes a string of type VARCHAR2 or CLOB as input, converts it to a vector, and returns a vector as output. TO_VECTOR also takes another vector as input, adjusts its format, and returns the adjusted vector as output. TO_VECTOR is synonymous with VECTOR.

Syntax

Description of the illustration to_vector.eps

Parameters

• expr must evaluate to one of:

  • A string that represents a vector. Accepted input data types for the string are character data types, JSON, CLOB, and BLOB .

    If a BLOB is used as the input parameter, it must represent the vector binary bytes.

  • A vector. If the input is a vector, then the function converts it to the format specified or to the default format if the format is not specified.

  If expr is NULL, the result is NULL.

  The string representation of the vector must be in the form of an array of non-null numbers enclosed with a bracket and separated by commas, such as [1, 3.4, -05.60, 3e+4]. TO_VECTOR converts a valid string representation of a vector to a vector in the format specified. If no format is specified the default format is used.

• number_of_dimensions must be a numeric value that describes the number of dimensions of the vector to construct. The number of dimensions may also be specified as an asterisk (*), in which case the dimension is determined by expr.

• format must be one of the following tokens: INT8, FLOAT32, FLOAT64, or *. This is the target internal storage format of the vector. If * is used, the format will be FLOAT32.

  Note that this behavior is different from declaring a vector column. When you declare a column of type VECTOR(3, *), then all inserted vectors will be stored as is without a change in format.

Examples

SELECT TO_VECTOR('[34.6, 77.8]');
SELECT TO_VECTOR('[34.6, 77.8]', 2, FLOAT32);

SELECT TO_VECTOR('[34.6, 77.8]', 2, FLOAT32) FROM dual;

TO_VECTOR('[34.6,77.8]',2,FLOAT32)
---------------------------------------------------------
[3.45999985E+001,7.78000031E+001]

1 row selected.

SELECT TO_VECTOR('[34.6, 77.8, -89.34]', 3, FLOAT32);

TO_VECTOR('[34.6,77.8,-89.34]',3,FLOAT32)
-----------------------------------------------------------
[3.45999985E+001,7.78000031E+001,-8.93399963E+001]

1 row selected.

Note:

• For applications using Oracle Client libraries prior to 23ai connected to Oracle Database 23ai, use the TO_VECTOR function to insert vector data. For example:

  INSERT INTO vecTab VALUES(TO_VECTOR('[1.1, 2.9, 3.14]'));

• Applications using Oracle Client 23ai libraries or Thin mode drivers can insert vector data directly as a string or a CLOB. For example:

  INSERT INTO vecTab VALUES ('[1.1, 2.9, 3.14]');