Function create_pg_search_pool 

pub async fn create_pg_search_pool(
    database_url: &str,
    max_connections: u32,
) -> Result<Pool<Postgres>, OperationOutcomeError>

Creates a separate PostgreSQL connection pool for the search index database.

Errors

Returns an error if the pool cannot open its first connection — an unreachable host, bad credentials, or a malformed database_url.