Method is_maintained

src/sql/src/plan/query.rs:6524–6533

Maintained dataflows can't have a finishing applied directly. Therefore, the finishing is turned into a `TopK`.

(&self)

    /// Maintained dataflows can't have a finishing applied directly. Therefore, the finishing is
    /// turned into a `TopK`.
    pub fn is_maintained(&self) -> bool {
        match self {
            QueryLifetime::OneShot => false,
            QueryLifetime::Index => true,
            QueryLifetime::MaterializedView => true,
            QueryLifetime::Subscribe => true,
            QueryLifetime::View => true,
            QueryLifetime::Source => true,
        }
    }

    /// Most maintained dataflows don't allow SHOW commands currently. However, SUBSCRIBE does.
    pub fn allow_show(&self) -> bool {