N+1 Query Problem in api manage/connector-status

[t0nem1n]

It appears that there might be an N+1 query problem in the api manage/connector-status. It impacts performance, makes the API slow.

    return [
        BasicCCPairInfo(
            has_successful_run=cc_pair.last_successful_index_time is not None,
            source=cc_pair.connector.source,
        )
        for cc_pair in cc_pairs
        if cc_pair.connector.source != DocumentSource.INGESTION_API
    ]

the line source=cc_pair.connector.source will run the query to get connector.source in the for loop.

I think we can fix it by add a left join to prevent this n+1 query problem.