PostgreSQL array_dims() Function

The PostgreSQL array_dims() function returns a text representing the dimensions of the specified array.

array_dims() Syntax

This is the syntax of the PostgreSQL array_dims() function:

array_dims(array) -> text

Parameters

array

Required. The array to check.

Return value

The PostgreSQL array_dims() function returns a text that represents dimensions of the specified array.

If the parameter array is NULL, the array_dims() function will give an error message.

array_dims() Examples

This example shows how to use the PostgreSQL array_dims() function to obtain dimension information of the array {0,1,2}.

SELECT array_dims(ARRAY[0, 1, 2]);

 array_dims
------------
 [1:3]

Here, the text [1:3] represents that [0, 1, 2] is a one-dimensional array with index from 1 to 3.

Let’s use the the PostgreSQL array_dims() function to obtain the dimension information of a two-digit array, for example:

SELECT array_dims(ARRAY[[1,2], [3,4], [5,6]]);

 array_dims
------------
 [1:3][1:2]

Here, the text [1:3][1:2] represents that [[1,2], [3,4], [5,6]] is a two-dimensional array, where the first dimension array had index from 1 to 3, and the second dimension array had index from 1 to 2.

SELECT
  array_dims(
    ARRAY[
      [[1,2,3], [4,5,6]],
      [[7,8,9], [0,0,0]],
      [[0,0,0], [0,0,0]]
    ]
  );

   array_dims
-----------------
 [1:3][1:2][1:3]

Here, the text [1:3][1:2][1:3] represents that the array specified is a three-dimensional array:

• The first dimension of the array has index from 1 to 3
• The second dimension of the array has index from 1 to 2
• The third dimension of the array has index from 1 to 3