[BUG] OpenSearch only ingests and stores the first element of an array and discards the rest

[A-Gray-Cat]

What is the bug?
When ingesting documents, or creating a materialized view / covering index in OpenSearch, if the original log line includes a JSON array (see example below), after ingestion (or materalized view / covering index creation), only the first element of the JSON array would get ingested and stored, and the rest of them would get discarded.

• Original log line

{
    ...
    "resources": [{"name": "bucket1"}, {"name": "bucket2"}, {"name": "bucket3"}]
}

• After ingestion or MV/CI creation

{
    ...
    "resources": {"name": "bucket1"}

}

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

1. Identify an original log line that includes an array.
2. Either using the ingestion pipeline, or create a MV/CI to ingest that identified log line.
3. Run a query to select that field, e.g. SELECT resources FROM table

What is the expected behavior?
The retrieved field will be the first element of the array, and the rest of elements of the array got discarded.

What is your host/environment?

• OS: [e.g. iOS]
• Version [e.g. 22]
• Plugins

Do you have any screenshots?
If applicable, add screenshots to help explain your problem.

Do you have any additional context?
Add any other context about the problem.