Extract all objects from json array using MariaDB 10.3
You can accomplish this by using a dedicated numbers_table. This is a table with a single column number and can have as many values as you require (I have 0 to 999)
For your question, there are two scenarios: The first is if you do not know the keys, or they change. The second is if you do know the keys and in this case you can get each key of the json objects as a column.
Scenario 1:
SELECT 
    JSON_VALUE(JSON_KEYS(@json_doc,CONCAT('$[',n1.number,']')),CONCAT('$[',n2.number,']')) AS json_column,
    JSON_VALUE(JSON_QUERY(@json_doc,CONCAT('$[',n1.number,']')),CONCAT('$.',JSON_VALUE(JSON_KEYS(@json_doc,CONCAT('$[',n1.number,']')),CONCAT('$[',n2.number,']')))) AS json_data,
    n2.number AS column_index,
    n1.number AS array_index
FROM numbers_table AS n1
JOIN numbers_table AS n2
WHERE 
    n1.number &lt; json_length(@json_doc) AND
    n2.number &lt; json_length(json_keys(@json_doc,CONCAT('$[',n1.number,']')));

-------------------------------------------------------
|json_column     |json_data |column_index |array_index|
|DatabaseName    |master    |0            |0          |
|Schema Name     |dbo       |1            |0          |
|Object Name     |CommandLog|2            |0          |
|column_index_id |1         |3            |0          |
|Buffer size(MB) |0.02      |4            |0          |
|BufferCount     |2         |5            |0          |
|Row Count       |3         |6            |0          |
|Compression Type|NONE      |7            |0          |
|DatabaseName    |master    |0            |1          |
|Schema Name     |dbo       |1            |1          |
|Object Name     |xevents   |2            |1          |
|column_index_id |0         |3            |1          |
|Buffer size(MB) |0.16      |4            |1          |
|BufferCount     |21        |5            |1          |
|Row Count       |0         |6            |1          |
|Compression Type|NONE      |7            |1          |

Scenario 2:
SELECT 
    n1.number AS array_index,
    JSON_VALUE(JSON_QUERY(@json_doc,CONCAT('$[',n1.number,']')),'$.DatabaseName') AS 'DatabaseName',
    JSON_VALUE(JSON_QUERY(@json_doc,CONCAT('$[',n1.number,']')),'$.Schema Name') AS 'Schema Name',
    JSON_VALUE(JSON_QUERY(@json_doc,CONCAT('$[',n1.number,']')),'$.Object Name') AS 'Object Name',
    JSON_VALUE(JSON_QUERY(@json_doc,CONCAT('$[',n1.number,']')),'$.column_index_id') AS 'column_index_id',
    JSON_VALUE(JSON_QUERY(@json_doc,CONCAT('$[',n1.number,']')),'$.Buffer size(MB)') AS 'Buffer size(MB)',
    JSON_VALUE(JSON_QUERY(@json_doc,CONCAT('$[',n1.number,']')),'$.BufferCount') AS 'BufferCount',
    JSON_VALUE(JSON_QUERY(@json_doc,CONCAT('$[',n1.number,']')),'$.Row Count') AS 'Row Count',
    JSON_VALUE(JSON_QUERY(@json_doc,CONCAT('$[',n1.number,']')),'$.Compression Type') AS 'Compression Type'
FROM numbers_table AS n1
WHERE 
    n1.number &lt; json_length(@json_doc);

Output:
|array_index|DatabaseName|Schema Name|Object Name|column_index_id|Buffer size(MB)|BufferCount|Row Count|Compression Type|
|0          |master      |dbo        |CommandLog |1              |0.02           |2          |3        |NONE            |
|1          |master      |dbo        |xevents    |0              |0.16           |21         |0        |NONE            |