[BUG] Columns (fields) with dot in the name are processed incorrectly

[Yury-Fridlyand]

What is the bug?
See examples below

How can one reproduce the bug?
Steps to reproduce the behavior:

1. Create a doc with a dot in a field name:

curl -X POST "localhost:9200/test/_doc/?pretty" -H 'Content-Type: application/json' -d '{ "account.number" : 42 }'

2. Query index:

select * from test

or PPL:

source=test

3. Response:
   SQL:

{
    "schema": [
        {
            "name": "account",
            "type": "object"
        }
    ],
    "datarows": [
        [
            null
        ]
    ],
    "total": 1,
    "size": 1,
    "status": 200
}

PPL:

{
    "schema": [
        {
            "name": "account",
            "type": "struct"
        }
    ],
    "datarows": [
        [
            null
        ]
    ],
    "total": 1,
    "size": 1
}

Or as a table

+-----------+
| account   |
|-----------|
| null      |
+-----------+

Specifying exact column name works fine though

What is the expected behavior?
Plugin should process dots in column names correctly.

+------------------+
| account.number   |
|------------------|
| 42               |
+------------------+

What is your host/environment?
main @ 34cad6e

Do you have any screenshots?
N/A

Do you have any additional context?
N/A

[forestmvey]

Is a bug on the OpenSearch side. Not a valid use-case for SQL plugin to handle and so I think this can be closed!

8748

[MaxKsyunz]

FYI this works ok to access properties of object fields.

If the mapping for field resource is object and it has a property called service.name, then select resource.service.name from ss4o_traces-default-namespace limit 1 will return the correct value.