Function fetch_metadata_partition_spec 

pub async fn fetch_metadata_partition_spec(
    pool: &Pool<Postgres>,
    source_count_query: &str,
    data_sql: Arc<String>,
    view_metadata: ViewMetadata,
    schema: Arc<Schema>,
    insert_range: TimeRange,
    compute_time_bounds: Arc<dyn DataFrameTimeBounds>,
) -> Result<MetadataPartitionSpec, Error>