flow/batching_mode/

task.rs

// Copyright 2023 Greptime Team
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use std::collections::{BTreeMap, BTreeSet, HashMap, HashSet};
use std::sync::{Arc, RwLock};
use std::time::{Duration, SystemTime, UNIX_EPOCH};

use api::v1::{CreateTableExpr, TableName};
use catalog::CatalogManagerRef;
use catalog::kvbackend::KvBackendCatalogManager;
use client::OutputWithMetrics;
use common_error::ext::BoxedError;
use common_meta::key::schema_name::SchemaNameKey;
use common_query::OutputData;
use common_query::logical_plan::breakup_insert_plan;
use common_telemetry::tracing::warn;
use common_telemetry::{debug, info};
use common_time::{TimeToLive, Timestamp};
use datafusion::datasource::DefaultTableSource;
use datafusion::sql::unparser::expr_to_sql;
use datafusion_common::tree_node::{Transformed, TreeNode};
use datafusion_common::utils::quote_identifier;
use datafusion_common::{DFSchemaRef, ScalarValue, TableReference};
use datafusion_expr::{DmlStatement, LogicalPlan, Projection, WriteOp, col, lit};
use datatypes::schema::Schema;
use datatypes::vectors::Helper;
use futures::TryStreamExt;
use query::QueryEngineRef;
use query::options::{
    FLOW_INCREMENTAL_AFTER_SEQS, FLOW_INCREMENTAL_MODE, FLOW_INCREMENTAL_MODE_SEQUENCE_RANGE,
    FLOW_RETURN_REGION_SEQ,
};
use query::query_engine::DefaultSerializer;
use session::context::QueryContextRef;
use snafu::{OptionExt, ResultExt};
use sql::parsers::utils::is_tql;
use store_api::mito_engine_options::MERGE_MODE_KEY;
use substrait::{DFLogicalSubstraitConvertor, SubstraitPlan};
use table::TableRef;
use table::table::adapter::DfTableProviderAdapter;
use tokio::sync::oneshot::error::TryRecvError;
use tokio::sync::{Mutex, OwnedMutexGuard, oneshot};
use tokio::time::Instant;

use crate::batching_mode::BatchingModeOptions;
use crate::batching_mode::checkpoint::checkpoint_mode_label;
use crate::batching_mode::eval_schedule::{EvalSchedule, select_due_scheduled_times};
use crate::batching_mode::frontend_client::{FrontendClient, PeerDesc};
use crate::batching_mode::state::{
    CheckpointMode, DirtyTimeWindows, FilterExprInfo, TaskState, to_df_literal,
};
use crate::batching_mode::table_creator::{QueryType, create_table_with_expr};
use crate::batching_mode::time_window::TimeWindowExpr;
use crate::batching_mode::utils::{
    AddFilterRewriter, ColumnMatcherRewriter, analyze_incremental_aggregate_plan, df_plan_to_sql,
    gen_plan_with_matching_schema_and_values, get_table_info_df_schema, sql_to_df_plan,
};
use crate::df_optimizer::apply_df_optimizer;
use crate::error::{
    DatafusionSnafu, ExternalSnafu, InvalidQuerySnafu, SubstraitEncodeLogicalPlanSnafu,
    UnexpectedSnafu,
};
use crate::metrics::{
    METRIC_FLOW_BATCHING_ENGINE_ERROR_CNT, METRIC_FLOW_BATCHING_ENGINE_QUERY_TIME,
    METRIC_FLOW_BATCHING_ENGINE_SLOW_QUERY, METRIC_FLOW_BATCHING_ENGINE_START_QUERY_CNT,
    METRIC_FLOW_ROWS,
};
use crate::{Error, FlowId};

mod ckpt;
mod inc;

/// Returns the current wall-clock Unix timestamp in seconds.
fn wall_clock_unix_secs() -> i64 {
    SystemTime::now()
        .duration_since(UNIX_EPOCH)
        .unwrap_or_default()
        .as_secs() as i64
}

/// Initial scheduler cursor for `start_scheduled_loop`: exactly one interval
/// before `start_secs` so the first due scheduled time is `start_secs` itself.
///
/// Fallible: a `start_secs - interval_secs` difference that does not fit in
/// `i64` is an explicit error instead of a saturated cursor that would make
/// the first due scheduled time `start_secs + interval_secs` and silently skip
/// the `start_secs` tick.
fn initial_schedule_cursor(start_secs: i64, interval_secs: i64) -> Result<i64, Error> {
    let cursor = i128::from(start_secs) - i128::from(interval_secs);
    i64::try_from(cursor).map_err(|_| {
        UnexpectedSnafu {
            reason: format!(
                "Cannot compute the initial eval schedule cursor one interval before start {start_secs} (interval={interval_secs}): {cursor} does not fit in i64"
            ),
        }
        .build()
    })
}

/// Whole seconds to sleep until the next scheduled time `next`, measured from
/// the current wall clock `wall_now_secs`.
///
/// Fallible: `next` must be strictly after `wall_now_secs` and the difference
/// must fit in `u64`. In practice `i64::MAX - i64::MIN` is exactly `u64::MAX`,
/// so the difference always fits once `next > wall_now_secs`; the explicit
/// error keeps the scheduled loop panic-free and wrap-free regardless.
fn sleep_delta_secs(next: i64, wall_now_secs: i64) -> Result<u64, Error> {
    let delta = i128::from(next) - i128::from(wall_now_secs);
    u64::try_from(delta).map_err(|_| {
        UnexpectedSnafu {
            reason: format!(
                "Cannot sleep until the next scheduled time {next}: the delta from wall clock {wall_now_secs} is {delta} seconds, which does not fit in u64"
            ),
        }
        .build()
    })
}

/// Scheduled time in seconds converted to milliseconds for the
/// `FLOW_SCHEDULED_TIME_MILLIS` extension.
///
/// Fallible: a seconds value whose millisecond product does not fit in `i64`
/// is an explicit error instead of a saturated `i64::MAX` that would silently
/// misrepresent the logical scheduled time.
fn scheduled_time_millis(scheduled_time_secs: i64) -> Result<i64, Error> {
    scheduled_time_secs.checked_mul(1000).ok_or_else(|| {
        UnexpectedSnafu {
            reason: format!(
                "Cannot convert scheduled time {scheduled_time_secs}s to milliseconds: the product exceeds i64"
            ),
        }
        .build()
    })
}

/// The task's config, immutable once created
#[derive(Clone)]
pub struct TaskConfig {
    pub flow_id: FlowId,
    pub query: String,
    /// output schema of the query
    pub output_schema: DFSchemaRef,
    pub time_window_expr: Option<TimeWindowExpr>,
    /// in seconds
    pub expire_after: Option<i64>,
    pub sink_table_name: [String; 3],
    pub source_table_names: HashSet<[String; 3]>,
    pub catalog_manager: CatalogManagerRef,
    pub query_type: QueryType,
    pub batch_opts: Arc<BatchingModeOptions>,
    pub exact_sequence_range_required: bool,
    pub flow_eval_interval: Option<Duration>,
    /// Typed schedule configuration, pre-parsed at task creation time.
    pub eval_schedule: Option<EvalSchedule>,
}

fn determine_query_type(query: &str, query_ctx: &QueryContextRef) -> Result<QueryType, Error> {
    let is_tql = is_tql(query_ctx.sql_dialect(), query)
        .map_err(BoxedError::new)
        .context(ExternalSnafu)?;
    Ok(if is_tql {
        QueryType::Tql
    } else {
        QueryType::Sql
    })
}

fn is_merge_mode_last_non_null(options: &HashMap<String, String>) -> bool {
    options
        .get(MERGE_MODE_KEY)
        .map(|mode| mode.eq_ignore_ascii_case("last_non_null"))
        .unwrap_or(false)
}

fn encode_insert_plan_request(
    insert_to: TableName,
    insert_input_plan: &LogicalPlan,
) -> Result<api::v1::QueryRequest, Error> {
    let message = DFLogicalSubstraitConvertor {}
        .encode(insert_input_plan, DefaultSerializer)
        .context(SubstraitEncodeLogicalPlanSnafu)?;
    Ok(api::v1::QueryRequest {
        query: Some(api::v1::query_request::Query::InsertIntoPlan(
            api::v1::InsertIntoPlan {
                table_name: Some(insert_to),
                logical_plan: message.to_vec(),
            },
        )),
    })
}

fn recovery_aggregate_input(plan: &LogicalPlan) -> Result<LogicalPlan, Error> {
    let plan = match plan {
        LogicalPlan::Projection(projection) => projection.input.as_ref(),
        _ => plan,
    };
    let LogicalPlan::Aggregate(aggregate) = plan else {
        return UnexpectedSnafu {
            reason: "Recovery timestamp projection did not find an aggregate".to_string(),
        }
        .fail();
    };
    Ok(aggregate.input.as_ref().clone())
}

fn capture_recovery_batch_windows(
    batch: &common_recordbatch::RecordBatch,
    time_window_expr: &TimeWindowExpr,
    windows: &mut BTreeSet<(Timestamp, Timestamp)>,
) -> Result<(), Error> {
    if batch.num_columns() != 1 {
        return UnexpectedSnafu {
            reason: format!(
                "Recovery timestamp projection returned {} columns instead of one",
                batch.num_columns()
            ),
        }
        .fail();
    }
    let values = Helper::try_into_vector(batch.column(0).clone())
        .map_err(BoxedError::new)
        .context(ExternalSnafu)?;
    for index in 0..values.len() {
        let timestamp = values.get(index).as_timestamp().context(UnexpectedSnafu {
            reason: "Recovery timestamp projection returned a null or non-timestamp value"
                .to_string(),
        })?;
        let (start, end) = time_window_expr.eval(timestamp)?;
        let window = (
            start.context(UnexpectedSnafu {
                reason: "Recovery time-window expression returned no lower bound".to_string(),
            })?,
            end.context(UnexpectedSnafu {
                reason: "Recovery time-window expression returned no upper bound".to_string(),
            })?,
        );
        windows.insert(window);
    }
    Ok(())
}

fn format_insert_target_columns(plan: &LogicalPlan) -> String {
    plan.schema()
        .fields()
        .iter()
        .map(|field| quote_identifier(field.name()).to_string())
        .collect::<Vec<_>>()
        .join(", ")
}

/// Owns a whole serialized execution round. It may be moved to an execution
/// collaborator, so cancellation of the caller cannot release the round early.
pub struct BatchingExecutionGuard {
    _lock: OwnedMutexGuard<()>,
    restore: Option<(Arc<RwLock<TaskState>>, QueryContextRef)>,
}

impl BatchingExecutionGuard {
    fn new(lock: OwnedMutexGuard<()>) -> Self {
        Self {
            _lock: lock,
            restore: None,
        }
    }

    fn restore_query_context(&mut self, state: Arc<RwLock<TaskState>>, old_ctx: QueryContextRef) {
        self.restore = Some((state, old_ctx));
    }
}

impl Drop for BatchingExecutionGuard {
    fn drop(&mut self) {
        if let Some((state, old_ctx)) = self.restore.take()
            && let Ok(mut state) = state.write()
        {
            state.query_ctx = old_ctx;
        }
    }
}

#[derive(Clone)]
pub struct BatchingTask {
    pub config: Arc<TaskConfig>,
    pub state: Arc<RwLock<TaskState>>,
    /// Serializes plan generation, execution, checkpoint advancement, and dirty
    /// window restoration for this flow. Without this, a manual flush and the
    /// background loop can process the same checkpoint range concurrently.
    execution_lock: Arc<Mutex<()>>,
    execution: Option<Arc<dyn crate::BatchingExecution>>,
}

/// Arguments for creating batching task
pub struct TaskArgs<'a> {
    pub flow_id: FlowId,
    pub query: &'a str,
    pub plan: LogicalPlan,
    pub time_window_expr: Option<TimeWindowExpr>,
    pub expire_after: Option<i64>,
    pub sink_table_name: [String; 3],
    pub source_table_names: Vec<[String; 3]>,
    pub query_ctx: QueryContextRef,
    pub catalog_manager: CatalogManagerRef,
    pub shutdown_rx: oneshot::Receiver<()>,
    pub batch_opts: Arc<BatchingModeOptions>,
    pub flow_eval_interval: Option<Duration>,
    /// Typed schedule configuration pre-parsed from `CreateFlowArgs`.
    pub eval_schedule: Option<EvalSchedule>,
}

pub struct PlanInfo {
    pub plan: LogicalPlan,
    pub dirty_restore: DirtyRestore,
    pub coverage: QueryCoverage,
}

#[derive(Clone)]
pub enum QueryCoverage {
    /// Explicit full-query snapshot coverage, e.g. TQL or evaluation-interval
    /// SQL flows whose plan shape cannot be safely dirty-window pruned. This
    /// must not be used as an implicit recovery path for scoped repair or an
    /// unsafe incremental rewrite fallback.
    UnfilteredFull,
    /// Scoped full-snapshot repair over the current dirty windows. A successful
    /// result may start a fenced repair if new dirty windows appeared meanwhile.
    ScopedBaseRepair,
    /// A chunk of windows being repaired under the frozen high-watermark `H`.
    /// The `high` map is sent as snapshot read bounds and must be matched by
    /// the returned terminal watermarks before checkpoints can advance.
    FencedRepairChunk { high: BTreeMap<u64, u64> },
    /// Incremental delta query over `(checkpoint, scan-open snapshot]`.
    IncrementalDelta,
}

impl QueryCoverage {
    /// Whether this query should use incremental scan extensions and
    /// incremental checkpoint advancement rules.
    fn is_incremental_delta(&self) -> bool {
        matches!(self, Self::IncrementalDelta)
    }

    /// Snapshot upper bounds requested from the storage layer. Only fenced
    /// repair chunks carry bounds; all other coverage relies on normal scans.
    fn snapshot_seqs(&self) -> HashMap<u64, u64> {
        match self {
            Self::FencedRepairChunk { high } => high.iter().map(|(k, v)| (*k, *v)).collect(),
            _ => HashMap::new(),
        }
    }
}

pub enum DirtyRestore {
    /// The query was scoped to dirty time ranges; restore those ranges if the
    /// run fails.
    Scoped(FilterExprInfo),
    /// The query could not be scoped to dirty time ranges, so the dirty-window
    /// state is only a dirty signal. Restore the consumed signal if the full
    /// run fails.
    ///
    /// TODO(discord9): Full-query runs only need a dirty bool flag. Refactor
    /// the unscoped path to stop reusing `DirtyTimeWindows` for this signal.
    Unscoped(DirtyTimeWindows),
}

pub struct ExecuteOnceOutcome {
    pub new_query: Option<PlanInfo>,
    /// Execution result of the generated insert plan.
    ///
    /// `Ok(Some((affected_rows, elapsed)))` means a query was executed.
    /// `Ok(None)` means no query was generated because there was no dirty signal.
    /// `Err(_)` means plan generation or execution failed.
    pub result: Result<Option<(usize, Duration)>, Error>,
}

impl BatchingTask {
    #[allow(clippy::too_many_arguments)]
    pub fn try_new(args: TaskArgs<'_>) -> Result<Self, Error> {
        Self::try_new_with_exact_sequence_range_required(args, false)
    }

    pub fn try_new_with_exact_sequence_range_required(
        TaskArgs {
            flow_id,
            query,
            plan,
            time_window_expr,
            expire_after,
            sink_table_name,
            source_table_names,
            query_ctx,
            catalog_manager,
            shutdown_rx,
            batch_opts,
            flow_eval_interval,
            eval_schedule,
        }: TaskArgs<'_>,
        exact_sequence_range_required: bool,
    ) -> Result<Self, Error> {
        let mut state = TaskState::with_dirty_time_windows(
            query_ctx.clone(),
            shutdown_rx,
            DirtyTimeWindows::new(
                batch_opts.experimental_max_filter_num_per_query,
                batch_opts.experimental_time_window_merge_threshold,
            ),
        );
        if !batch_opts.experimental_enable_incremental_read {
            state.disable_incremental();
        }

        Ok(Self {
            config: Arc::new(TaskConfig {
                flow_id,
                query: query.to_string(),
                time_window_expr,
                expire_after,
                sink_table_name,
                source_table_names: source_table_names.into_iter().collect(),
                catalog_manager,
                output_schema: plan.schema().clone(),
                query_type: determine_query_type(query, &query_ctx)?,
                exact_sequence_range_required,
                batch_opts,
                flow_eval_interval,
                eval_schedule,
            }),
            state: Arc::new(RwLock::new(state)),
            execution_lock: Arc::new(Mutex::new(())),
            execution: None,
        })
    }

    pub(crate) fn with_execution(
        mut self,
        execution: Option<Arc<dyn crate::BatchingExecution>>,
    ) -> Self {
        self.execution = execution;
        self
    }

    pub(crate) fn stop_execution(&self) {
        if let Some(execution) = &self.execution {
            execution.stop();
        }
    }

    pub fn last_execution_time_millis(&self) -> Option<i64> {
        self.state.read().unwrap().last_execution_time_millis()
    }

    pub fn start_time_millis(&self) -> Option<i64> {
        self.state.read().unwrap().start_time_millis()
    }

    /// Collect flow-related extensions from the task's query context that should be
    /// forwarded to the frontend (e.g. scheduled time).
    fn frontend_extensions(&self) -> HashMap<String, String> {
        let ctx = self.state.read().unwrap();
        let all = ctx.query_ctx.extensions();
        let mut flow_exts = HashMap::new();
        // Propagate the scheduled time extension if present so that frontend
        // execution can use the same logical time.
        if let Some(v) = all.get(query::options::FLOW_SCHEDULED_TIME_MILLIS) {
            flow_exts.insert(
                query::options::FLOW_SCHEDULED_TIME_MILLIS.to_string(),
                v.clone(),
            );
        }
        flow_exts
    }

    /// mark time window range (now - expire_after, now) as dirty (or (0, now) if expire_after not set)
    ///
    /// useful for flush_flow to flush dirty time windows range
    pub fn mark_all_windows_as_dirty(&self) -> Result<(), Error> {
        let now = SystemTime::now();
        let now = Timestamp::new_second(
            now.duration_since(UNIX_EPOCH)
                .expect("Time went backwards")
                .as_secs() as _,
        );
        let lower_bound = self
            .config
            .expire_after
            .map(|e| now.sub_duration(Duration::from_secs(e as _)))
            .transpose()
            .map_err(BoxedError::new)
            .context(ExternalSnafu)?
            .unwrap_or(Timestamp::new_second(0));
        debug!(
            "Flow {} mark range ({:?}, {:?}) as dirty",
            self.config.flow_id, lower_bound, now
        );
        self.state
            .write()
            .unwrap()
            .dirty_time_windows
            .add_window(lower_bound, Some(now));
        Ok(())
    }

    /// Create the sink table if needed, then return it.
    pub async fn check_or_create_sink_table(
        &self,
        engine: &QueryEngineRef,
        frontend_client: &Arc<FrontendClient>,
    ) -> Result<TableRef, Error> {
        if !self.is_table_exist(&self.config.sink_table_name).await? {
            let create_table = self.gen_create_table_expr(engine.clone()).await?;
            info!(
                "Try creating sink table(if not exists) with expr: {:?}",
                create_table
            );
            self.create_table(frontend_client, create_table).await?;
            info!(
                "Sink table {}(if not exists) created",
                self.config.sink_table_name.join(".")
            );
        }
        let (table, _) = get_table_info_df_schema(
            self.config.catalog_manager.clone(),
            self.config.sink_table_name.clone(),
        )
        .await?;
        Ok(table)
    }

    /// Returns a forked snapshot of the task query context for extension-owned planning.
    pub fn query_context_snapshot(&self) -> QueryContextRef {
        let query_ctx = self.state.read().unwrap().query_ctx.clone();
        Arc::new(query_ctx.fork())
    }

    /// Returns the retention lower bound aligned to this task's time window.
    pub fn recovery_retention_lower_bound(&self) -> Result<Option<Timestamp>, Error> {
        let Some(expire_after) = self.config.expire_after else {
            return Ok(None);
        };
        let expire_after = u64::try_from(expire_after).map_err(|_| {
            UnexpectedSnafu {
                reason: format!(
                    "Flow {} has negative expire_after {expire_after}",
                    self.config.flow_id
                ),
            }
            .build()
        })?;
        let now = Timestamp::new_second(
            SystemTime::now()
                .duration_since(UNIX_EPOCH)
                .map_err(|err| {
                    UnexpectedSnafu {
                        reason: format!("Failed to read recovery wall clock: {err}"),
                    }
                    .build()
                })?
                .as_secs() as i64,
        );
        let lower = now
            .sub_duration(Duration::from_secs(expire_after))
            .map_err(BoxedError::new)
            .context(ExternalSnafu)?;
        self.config
            .time_window_expr
            .as_ref()
            .context(UnexpectedSnafu {
                reason: "Recovery expiry requires a time-window expression".to_string(),
            })?
            .eval(lower)?
            .0
            .context(UnexpectedSnafu {
                reason: "Recovery expiry time-window expression returned no lower bound"
                    .to_string(),
            })
            .map(Some)
    }

    /// Verifies that recovery can still read all source data required by its retained scope.
    pub async fn validate_recovery_retention(
        &self,
        retention_lower: Option<Timestamp>,
        windows: &[(Timestamp, Timestamp)],
    ) -> Result<(), Error> {
        for name in &self.config.source_table_names {
            let table = self
                .config
                .catalog_manager
                .table(&name[0], &name[1], &name[2], None)
                .await
                .map_err(BoxedError::new)
                .context(ExternalSnafu)?
                .context(UnexpectedSnafu {
                    reason: format!(
                        "Flow {} source table {} is unavailable for recovery retention validation",
                        self.config.flow_id,
                        name.join(".")
                    ),
                })?;
            let ttl = if let Some(ttl) = table.table_info().meta.options.ttl {
                ttl
            } else {
                let manager = self
                    .config
                    .catalog_manager
                    .as_any()
                    .downcast_ref::<KvBackendCatalogManager>()
                    .context(UnexpectedSnafu {
                        reason: format!(
                            "Flow {} cannot resolve inherited TTL for source table {} during recovery",
                            self.config.flow_id,
                            name.join(".")
                        ),
                    })?;
                manager
                    .table_metadata_manager_ref()
                    .schema_manager()
                    .get(SchemaNameKey::new(&name[0], &name[1]))
                    .await
                    .map_err(BoxedError::new)
                    .context(ExternalSnafu)?
                    .context(UnexpectedSnafu {
                        reason: format!(
                            "Flow {} schema {}.{} is unavailable for recovery retention validation",
                            self.config.flow_id, name[0], name[1]
                        ),
                    })?
                    .ttl
                    .map(Into::into)
                    .unwrap_or(TimeToLive::Forever)
            };

            match ttl {
                TimeToLive::Forever => {}
                TimeToLive::Instant => {
                    return UnexpectedSnafu {
                        reason: format!(
                            "Flow {} source table {} has instant TTL and cannot be recovered",
                            self.config.flow_id,
                            name.join(".")
                        ),
                    }
                    .fail();
                }
                TimeToLive::Duration(ttl) => {
                    let expire_after = self.config.expire_after.context(UnexpectedSnafu {
                        reason: format!(
                            "Flow {} source table {} has TTL {ttl:?}, but recovery has no expire_after",
                            self.config.flow_id,
                            name.join(".")
                        ),
                    })?;
                    let expire_after = u64::try_from(expire_after).map_err(|_| {
                        UnexpectedSnafu {
                            reason: format!(
                                "Flow {} has negative expire_after {expire_after} during recovery retention validation",
                                self.config.flow_id
                            ),
                        }
                        .build()
                    })?;
                    if ttl <= Duration::from_secs(expire_after) {
                        return UnexpectedSnafu {
                            reason: format!(
                                "Flow {} source table {} TTL {ttl:?} must exceed expire_after {expire_after}s for recovery",
                                self.config.flow_id,
                                name.join(".")
                            ),
                        }
                        .fail();
                    }
                    let mut oldest = retention_lower.context(UnexpectedSnafu {
                        reason: format!(
                            "Flow {} source table {} has finite TTL {ttl:?}, but recovery has no retained lower bound",
                            self.config.flow_id,
                            name.join(".")
                        ),
                    })?;
                    for (start, _) in windows {
                        oldest = oldest.min(*start);
                    }
                    let cutoff = Timestamp::current_millis()
                        .sub_duration(ttl)
                        .map_err(BoxedError::new)
                        .context(ExternalSnafu)?;
                    if oldest <= cutoff {
                        return UnexpectedSnafu {
                            reason: format!(
                                "Flow {} recovery requires source table {} data from {oldest:?}, older than TTL {ttl:?} cutoff {cutoff:?}",
                                self.config.flow_id,
                                name.join(".")
                            ),
                        }
                        .fail();
                    }
                }
            }
        }
        Ok(())
    }

    /// Discovers the source time windows touched by the exact sequence range `(C, H]`.
    ///
    /// This compatibility wrapper captures the retention bound before discovery.
    pub async fn capture_recovery_windows(
        &self,
        engine: &QueryEngineRef,
        frontend_client: &FrontendClient,
        lower: &BTreeMap<u64, u64>,
    ) -> Result<(BTreeMap<u64, u64>, Vec<(Timestamp, Timestamp)>), Error> {
        let retention_lower = self.recovery_retention_lower_bound()?;
        self.capture_recovery_windows_since(engine, frontend_client, lower, retention_lower)
            .await
    }

    /// Discovers windows under `lower` using a caller-frozen retention bound.
    ///
    /// The caller owns the execution guard and freezes this bound with its recovery scope.
    /// This read-only method leaves task state untouched. Terminal proof must cover every
    /// region in `lower`; subset or pruned proofs are rejected.
    pub async fn capture_recovery_windows_since(
        &self,
        engine: &QueryEngineRef,
        frontend_client: &FrontendClient,
        lower: &BTreeMap<u64, u64>,
        retention_lower: Option<Timestamp>,
    ) -> Result<(BTreeMap<u64, u64>, Vec<(Timestamp, Timestamp)>), Error> {
        if lower.is_empty() {
            return UnexpectedSnafu {
                reason: format!(
                    "Flow {} recovery window capture requires nonempty lower sequence bounds",
                    self.config.flow_id
                ),
            }
            .fail();
        }
        if !self.sequence_range_capable().await? {
            return UnexpectedSnafu {
                reason: format!(
                    "Flow {} recovery window capture requires sequence_range-capable sources",
                    self.config.flow_id
                ),
            }
            .fail();
        }

        let query_ctx = self.query_context_snapshot();
        let plan = sql_to_df_plan(query_ctx, engine.clone(), &self.config.query, false).await?;
        let input = recovery_aggregate_input(&plan)?;
        let Some(analysis) = analyze_incremental_aggregate_plan(&plan)? else {
            return UnexpectedSnafu {
                reason: format!(
                    "Flow {} recovery window capture requires a supported aggregate input",
                    self.config.flow_id
                ),
            }
            .fail();
        };
        if !analysis.unsupported_exprs.is_empty() {
            return UnexpectedSnafu {
                reason: format!(
                    "Flow {} recovery window capture has unsupported aggregate expressions: {:?}",
                    self.config.flow_id, analysis.unsupported_exprs
                ),
            }
            .fail();
        }
        let time_window_expr = self
            .config
            .time_window_expr
            .as_ref()
            .context(UnexpectedSnafu {
                reason: format!(
                    "Flow {} recovery window capture requires a time-window expression",
                    self.config.flow_id
                ),
            })?;
        let input = if let Some(retention_lower) = retention_lower {
            let mut add_filter = AddFilterRewriter::new(
                col(&time_window_expr.column_name).gt_eq(lit(to_df_literal(retention_lower)?)),
            );
            input
                .rewrite(&mut add_filter)
                .with_context(|_| DatafusionSnafu {
                    context: "Failed to apply recovery expire_after filter".to_string(),
                })?
                .data
        } else {
            input
        };
        let timestamp_plan = LogicalPlan::Projection(
            Projection::try_new(vec![col(&time_window_expr.column_name)], Arc::new(input))
                .context(DatafusionSnafu {
                    context: "Failed to project recovery source timestamps".to_string(),
                })?,
        );
        let catalog = &self.config.sink_table_name[0];
        let schema = &self.config.sink_table_name[1];
        let timestamp_plan = timestamp_plan
            .clone()
            .transform_down_with_subqueries(|p| {
                if let LogicalPlan::TableScan(mut table_scan) = p {
                    let resolved = table_scan.table_name.resolve(catalog, schema);
                    table_scan.table_name = resolved.into();
                    Ok(Transformed::yes(LogicalPlan::TableScan(table_scan)))
                } else {
                    Ok(Transformed::no(p))
                }
            })
            .with_context(|_| DatafusionSnafu {
                context: format!(
                    "Failed to fix table ref in recovery timestamp plan, plan={:?}",
                    timestamp_plan
                ),
            })?
            .data;
        let message = DFLogicalSubstraitConvertor {}
            .encode(&timestamp_plan, DefaultSerializer)
            .context(SubstraitEncodeLogicalPlanSnafu)?;
        let request = api::v1::QueryRequest {
            query: Some(api::v1::query_request::Query::LogicalPlan(message.to_vec())),
        };
        let lower_json = serde_json::to_string(lower).map_err(|err| {
            UnexpectedSnafu {
                reason: format!("Failed to serialize recovery lower sequence bounds: {err}"),
            }
            .build()
        })?;
        let extensions = [
            (FLOW_RETURN_REGION_SEQ, "true"),
            (FLOW_INCREMENTAL_MODE, FLOW_INCREMENTAL_MODE_SEQUENCE_RANGE),
            (FLOW_INCREMENTAL_AFTER_SEQS, lower_json.as_str()),
        ];
        let mut peer_desc = None;
        let result = frontend_client
            .query_with_terminal_metrics(
                catalog,
                schema,
                request,
                &extensions,
                &HashMap::new(),
                &mut peer_desc,
            )
            .await?;
        let mut aligned_windows = BTreeSet::new();
        let metrics = result.metrics.clone();
        match result.output.data {
            OutputData::AffectedRows(_) => {
                return UnexpectedSnafu {
                    reason: "Recovery timestamp projection unexpectedly returned affected rows"
                        .to_string(),
                }
                .fail();
            }
            OutputData::RecordBatches(batches) => {
                for batch in batches.iter() {
                    capture_recovery_batch_windows(batch, time_window_expr, &mut aligned_windows)?;
                }
            }
            OutputData::Stream(mut stream) => {
                while let Some(batch) = stream
                    .try_next()
                    .await
                    .map_err(BoxedError::new)
                    .context(ExternalSnafu)?
                {
                    capture_recovery_batch_windows(&batch, time_window_expr, &mut aligned_windows)?;
                }
            }
        }
        if !metrics.is_ready() {
            return UnexpectedSnafu {
                reason: "Recovery timestamp projection ended without terminal metrics".to_string(),
            }
            .fail();
        }
        let participating = metrics.participating_regions().context(UnexpectedSnafu {
            reason: "Recovery timestamp projection has no participating-region proof".to_string(),
        })?;
        let high = metrics.region_watermark_map().context(UnexpectedSnafu {
            reason: "Recovery timestamp projection has no terminal watermark proof".to_string(),
        })?;
        if participating.len() != lower.len()
            || high.len() != lower.len()
            || participating
                .iter()
                .any(|region| !lower.contains_key(region))
            || lower
                .iter()
                .any(|(region, low)| high.get(region).is_none_or(|watermark| watermark < low))
            || high.keys().any(|region| !participating.contains(region))
        {
            return UnexpectedSnafu {
                reason: format!(
                    "Recovery timestamp projection returned incomplete or regressing terminal proof: lower={lower:?}, participating={participating:?}, high={high:?}"
                ),
            }
            .fail();
        }
        Ok((
            high.into_iter().collect(),
            aligned_windows.into_iter().collect(),
        ))
    }

    /// Validates that the sink table schema can accept this flow's ordinary output.
    pub async fn validate_sink_table_schema(&self, engine: &QueryEngineRef) -> Result<(), Error> {
        self.validate_sink_table_schema_with_values(engine, &BTreeMap::new())
            .await
    }

    /// Validates the flow output plus extension-owned typed sink values without consuming dirty work.
    pub async fn validate_sink_table_schema_with_values(
        &self,
        engine: &QueryEngineRef,
        values: &BTreeMap<String, ScalarValue>,
    ) -> Result<(), Error> {
        let (table, _) = get_table_info_df_schema(
            self.config.catalog_manager.clone(),
            self.config.sink_table_name.clone(),
        )
        .await?;

        let table_meta = &table.table_info().meta;
        let merge_mode_last_non_null =
            is_merge_mode_last_non_null(&table_meta.options.extra_options);
        let primary_key_indices = table_meta.primary_key_indices.clone();

        gen_plan_with_matching_schema_and_values(
            &self.config.query,
            self.query_context_snapshot(),
            engine.clone(),
            table_meta.schema.clone(),
            &primary_key_indices,
            merge_mode_last_non_null,
            values,
        )
        .await
        .map(|_| ())
    }

    async fn is_table_exist(&self, table_name: &[String; 3]) -> Result<bool, Error> {
        self.config
            .catalog_manager
            .table_exists(&table_name[0], &table_name[1], &table_name[2], None)
            .await
            .map_err(BoxedError::new)
            .context(ExternalSnafu)
    }

    pub(crate) async fn execute_once_serialized(
        &self,
        engine: &QueryEngineRef,
        frontend_client: &Arc<FrontendClient>,
        max_window_cnt: Option<usize>,
    ) -> Result<Option<(usize, Duration)>, Error> {
        let outcome = self
            .execute_once_serialized_with_outcome(engine, frontend_client, max_window_cnt)
            .await;
        outcome.result
    }

    /// Executes one flow evaluation under `execution_lock` and keeps the
    /// generated query context for the background loop's error logging/backoff.
    async fn execute_once_serialized_with_outcome(
        &self,
        engine: &QueryEngineRef,
        frontend_client: &Arc<FrontendClient>,
        max_window_cnt: Option<usize>,
    ) -> ExecuteOnceOutcome {
        let guard = BatchingExecutionGuard::new(self.execution_lock.clone().lock_owned().await);
        self.execute_once_with_guard(guard, engine, frontend_client, max_window_cnt)
            .await
    }

    async fn execute_once_with_guard(
        &self,
        guard: BatchingExecutionGuard,
        engine: &QueryEngineRef,
        frontend_client: &Arc<FrontendClient>,
        max_window_cnt: Option<usize>,
    ) -> ExecuteOnceOutcome {
        if let Some(execution) = &self.execution {
            return execution
                .clone()
                .execute_once(guard, self, engine, frontend_client, max_window_cnt)
                .await;
        }
        self.execute_once_default_unlocked(engine, frontend_client, max_window_cnt)
            .await
    }

    /// Executes the default flow evaluation. Caller owns the execution guard.
    async fn execute_once_default_unlocked(
        &self,
        engine: &QueryEngineRef,
        frontend_client: &Arc<FrontendClient>,
        max_window_cnt: Option<usize>,
    ) -> ExecuteOnceOutcome {
        let new_query = match self.gen_insert_plan_unlocked(engine, max_window_cnt).await {
            Ok(new_query) => new_query,
            Err(err) => {
                return ExecuteOnceOutcome {
                    new_query: None,
                    result: Err(err),
                };
            }
        };

        if let Some(new_query) = new_query {
            debug!("Generate new query: {}", new_query.plan);
            let res = self
                .execute_logical_plan_unlocked(
                    engine,
                    frontend_client,
                    &new_query.plan,
                    &new_query.dirty_restore,
                    &new_query.coverage,
                )
                .await;
            if res.is_err() {
                self.handle_executed_query_failure(Some(&new_query));
            }
            ExecuteOnceOutcome {
                new_query: Some(new_query),
                result: res,
            }
        } else {
            debug!("Generate no query");
            ExecuteOnceOutcome {
                new_query: None,
                result: Ok(None),
            }
        }
    }

    /// Generates the ordinary insert plan. Caller must reach this through the serialized path.
    async fn gen_insert_plan_unlocked(
        &self,
        engine: &QueryEngineRef,
        max_window_cnt: Option<usize>,
    ) -> Result<Option<PlanInfo>, Error> {
        self.gen_insert_plan_with_values_unlocked(engine, max_window_cnt, &BTreeMap::new(), false)
            .await
    }

    /// Generates the insert plan with extension-owned typed sink values. Caller must own the
    /// serialized execution guard.
    pub async fn gen_insert_plan_with_values_unlocked(
        &self,
        engine: &QueryEngineRef,
        max_window_cnt: Option<usize>,
        values: &BTreeMap<String, ScalarValue>,
        force_full_snapshot: bool,
    ) -> Result<Option<PlanInfo>, Error> {
        let (table, df_schema) = get_table_info_df_schema(
            self.config.catalog_manager.clone(),
            self.config.sink_table_name.clone(),
        )
        .await?;

        let table_meta = &table.table_info().meta;
        let merge_mode_last_non_null =
            is_merge_mode_last_non_null(&table_meta.options.extra_options);
        let primary_key_indices = table_meta.primary_key_indices.clone();

        let new_query = self
            .gen_query_with_time_window_with_values(
                engine.clone(),
                &table.table_info().meta.schema,
                &primary_key_indices,
                merge_mode_last_non_null,
                max_window_cnt,
                values,
                force_full_snapshot,
            )
            .await?;

        let Some(new_query) = new_query else {
            return Ok(None);
        };

        // first check if all columns in input query exists in sink table
        // since insert into ref to names in record batch generate by given query
        let table_columns = df_schema
            .columns()
            .into_iter()
            .map(|c| c.name)
            .collect::<BTreeSet<_>>();
        for column in new_query.plan.schema().columns() {
            if !table_columns.contains(column.name()) {
                self.restore_dirty_windows_after_failure(&new_query);
                return InvalidQuerySnafu {
                    reason: format!(
                        "Column {} not found in sink table with columns {:?}",
                        column, table_columns
                    ),
                }
                .fail();
            }
        }

        let table_provider = Arc::new(DfTableProviderAdapter::new(table));
        let table_source = Arc::new(DefaultTableSource::new(table_provider));

        // update_at& time index placeholder (if exists) should have default value
        let plan = LogicalPlan::Dml(DmlStatement::new(
            datafusion_common::TableReference::Full {
                catalog: self.config.sink_table_name[0].clone().into(),
                schema: self.config.sink_table_name[1].clone().into(),
                table: self.config.sink_table_name[2].clone().into(),
            },
            table_source,
            WriteOp::Insert(datafusion_expr::dml::InsertOp::Append),
            Arc::new(new_query.plan.clone()),
        ));
        let insert_into_info = PlanInfo {
            plan,
            dirty_restore: new_query.dirty_restore,
            coverage: new_query.coverage,
        };
        let insert_into =
            match insert_into_info
                .plan
                .clone()
                .recompute_schema()
                .context(DatafusionSnafu {
                    context: "Failed to recompute schema",
                }) {
                Ok(insert_into) => insert_into,
                Err(err) => {
                    self.restore_dirty_windows_after_failure(&insert_into_info);
                    return Err(err);
                }
            };

        Ok(Some(PlanInfo {
            plan: insert_into,
            dirty_restore: insert_into_info.dirty_restore,
            coverage: insert_into_info.coverage,
        }))
    }

    pub async fn create_table(
        &self,
        frontend_client: &Arc<FrontendClient>,
        expr: CreateTableExpr,
    ) -> Result<(), Error> {
        let catalog = &self.config.sink_table_name[0];
        let schema = &self.config.sink_table_name[1];
        frontend_client
            .create(expr.clone(), catalog, schema)
            .await?;
        Ok(())
    }

    /// Applies checkpoint state updates around the raw insert-plan execution.
    async fn execute_logical_plan_unlocked(
        &self,
        engine: &QueryEngineRef,
        frontend_client: &Arc<FrontendClient>,
        plan: &LogicalPlan,
        dirty_restore: &DirtyRestore,
        coverage: &QueryCoverage,
    ) -> Result<Option<(usize, Duration)>, Error> {
        let flow_id = self.config.flow_id;
        let Some((res, elapsed)) = self
            .execute_plan_unlocked(engine, frontend_client, plan, dirty_restore, coverage)
            .await?
        else {
            return Ok(None);
        };

        if let Err(err) = &res {
            let decision = {
                let mut state = self.state.write().unwrap();
                let reason = Self::query_failure_reason(err, coverage);
                Self::apply_query_failure_to_state(&mut state, elapsed, coverage, reason)
            };
            if let Some(decision) = decision {
                Self::record_checkpoint_decision(flow_id, decision);
            }
        }

        let res = res?;
        let (affected_rows, _) = res.output.extract_rows_and_cost();
        let decision = {
            let mut state = self.state.write().unwrap();
            Self::apply_query_result_to_state(&mut state, &res, elapsed, coverage)
        };
        Self::record_checkpoint_decision(flow_id, decision);
        Ok(Some((affected_rows, elapsed)))
    }

    /// Executes a fully constructed insert plan without checkpoint-state mutation.
    /// Callers must own the serialized execution guard. Its unsafe-incremental safety fallback
    /// still restores the supplied dirty work before returning `Ok(None)`.
    pub async fn execute_plan_unlocked(
        &self,
        engine: &QueryEngineRef,
        frontend_client: &Arc<FrontendClient>,
        plan: &LogicalPlan,
        dirty_restore: &DirtyRestore,
        coverage: &QueryCoverage,
    ) -> Result<Option<(Result<OutputWithMetrics, Error>, Duration)>, Error> {
        let instant = Instant::now();
        let flow_id = self.config.flow_id;

        debug!(
            "Executing flow {flow_id}(expire_after={:?} secs) with query {}",
            self.config.expire_after, &plan
        );

        let catalog = &self.config.sink_table_name[0];
        let schema = &self.config.sink_table_name[1];

        // fix all table ref by make it fully qualified, i.e. "table_name" => "catalog_name.schema_name.table_name"
        let plan = plan
            .clone()
            .transform_down_with_subqueries(|p| {
                if let LogicalPlan::TableScan(mut table_scan) = p {
                    let resolved = table_scan.table_name.resolve(catalog, schema);
                    table_scan.table_name = resolved.into();
                    Ok(Transformed::yes(LogicalPlan::TableScan(table_scan)))
                } else {
                    Ok(Transformed::no(p))
                }
            })
            .with_context(|_| DatafusionSnafu {
                context: format!("Failed to fix table ref in logical plan, plan={:?}", plan),
            })?
            .data;

        // For incremental-mode SQL queries, attempt to rewrite the delta aggregate
        // plan into a safe delta-LEFT-JOIN-sink form before deciding on extensions.
        let incremental_plan = if coverage.is_incremental_delta() {
            self.prepare_plan_for_incremental(engine, &plan).await?
        } else {
            None
        };
        let incremental_safe = incremental_plan.is_some();
        if coverage.is_incremental_delta() && !incremental_safe {
            debug!(
                "Flow {flow_id} skipped unsafe incremental delta fallback; \
                 restored dirty signal instead of executing an unfiltered full snapshot"
            );
            self.restore_dirty_windows(dirty_restore);
            return Ok(None);
        }
        let plan = incremental_plan.unwrap_or_else(|| plan.clone());
        let plan = match &self.execution {
            Some(execution) => execution.rewrite_plan(self, plan)?,
            None => plan,
        };

        let extensions = self
            .build_flow_query_extensions(incremental_safe, coverage.is_incremental_delta())
            .await?;
        let frontend_extensions = self.frontend_extensions();
        let extension_refs = extensions
            .iter()
            .map(|(key, value)| (*key, value.as_str()))
            .chain(
                frontend_extensions
                    .iter()
                    .map(|(key, value)| (key.as_str(), value.as_str())),
            )
            .collect::<Vec<_>>();
        let query_mode = if extensions
            .iter()
            .any(|(key, _)| *key == FLOW_INCREMENTAL_MODE)
        {
            CheckpointMode::Incremental
        } else {
            CheckpointMode::FullSnapshot
        };
        Self::record_query_mode(flow_id, query_mode);
        debug!(
            "Flow {flow_id} executing batching query with checkpoint_mode={}, extension_count={}",
            checkpoint_mode_label(query_mode),
            extensions.len()
        );

        let mut peer_desc = None;
        let res = {
            let _timer = METRIC_FLOW_BATCHING_ENGINE_QUERY_TIME
                .with_label_values(&[flow_id.to_string().as_str()])
                .start_timer();

            let req = if let Some((insert_to, insert_input_plan)) =
                breakup_insert_plan(&plan, catalog, schema)
            {
                if query_mode == CheckpointMode::FullSnapshot
                    && matches!(self.config.query_type, QueryType::Sql)
                    && self.config.flow_eval_interval.is_some()
                    && self.config.time_window_expr.is_none()
                {
                    // Evaluation-interval SQL flows without a time-window
                    // expression execute as full-query snapshots. Send these
                    // as SQL text instead of Substrait to avoid logical-plan
                    // round-trip issues around complex joins/unions/CTEs and
                    // duplicate field aliases. Keep ordinary SQL full snapshots
                    // on the existing InsertIntoPlan path because SQL unparsing
                    // is not valid for every planned aggregate shape yet.
                    // If the local SQL unparser does not support this plan,
                    // keep the previous InsertIntoPlan transport as a fallback.
                    match df_plan_to_sql(&insert_input_plan) {
                        Ok(select_sql) => {
                            let target_columns = format_insert_target_columns(&insert_input_plan);
                            let sql = format!(
                                "INSERT INTO {} ({}) {}",
                                TableReference::full(
                                    insert_to.catalog_name.as_str(),
                                    insert_to.schema_name.as_str(),
                                    insert_to.table_name.as_str(),
                                )
                                .to_quoted_string(),
                                target_columns,
                                select_sql
                            );
                            api::v1::QueryRequest {
                                query: Some(api::v1::query_request::Query::Sql(sql)),
                            }
                        }
                        Err(err) => {
                            debug!(
                                "Failed to unparse full-snapshot SQL flow {} plan; \
                                 falling back to InsertIntoPlan: {:?}",
                                flow_id, err
                            );
                            encode_insert_plan_request(insert_to, &insert_input_plan)?
                        }
                    }
                } else {
                    encode_insert_plan_request(insert_to, &insert_input_plan)?
                }
            } else {
                let message = DFLogicalSubstraitConvertor {}
                    .encode(&plan, DefaultSerializer)
                    .context(SubstraitEncodeLogicalPlanSnafu)?;

                api::v1::QueryRequest {
                    query: Some(api::v1::query_request::Query::LogicalPlan(message.to_vec())),
                }
            };

            let snapshot_seqs = coverage.snapshot_seqs();
            {
                let mut state = self.state.write().unwrap();
                state.record_start_time_if_first();
            }
            frontend_client
                .query_with_terminal_metrics(
                    catalog,
                    schema,
                    req,
                    &extension_refs,
                    &snapshot_seqs,
                    &mut peer_desc,
                )
                .await
        };

        let elapsed = instant.elapsed();
        let peer_label = peer_desc
            .as_ref()
            .map(ToString::to_string)
            .unwrap_or_else(|| PeerDesc::default().to_string());
        if let Err(err) = &res {
            // This raw helper deliberately leaves checkpoint transitions to its caller. The
            // default wrapper performs the single OSS transition; extension owners can persist
            // their durable marker before updating in-memory state.
            warn!(
                "Failed to execute Flow {flow_id} on frontend {peer_label}, result: {err:?}, elapsed: {:?} with query: {}",
                elapsed, &plan
            );
        }

        // record slow query
        if elapsed >= self.config.batch_opts.slow_query_threshold {
            warn!(
                "Flow {flow_id} on frontend {peer_label} executed for {:?} before complete, query: {}",
                elapsed, &plan
            );
            let flow_id = flow_id.to_string();
            METRIC_FLOW_BATCHING_ENGINE_SLOW_QUERY
                .with_label_values(&[flow_id.as_str(), peer_label.as_str()])
                .observe(elapsed.as_secs_f64());
        }

        match res {
            Ok(res) => {
                let (affected_rows, _) = res.output.extract_rows_and_cost();
                debug!(
                    "Flow {flow_id} executed, affected_rows: {affected_rows:?}, elapsed: {:?}, watermark: {:?}",
                    elapsed,
                    res.region_watermark_map()
                );
                METRIC_FLOW_ROWS
                    .with_label_values(&[format!("{}-out-batching", flow_id).as_str()])
                    .inc_by(affected_rows as _);
                Ok(Some((Ok(res), elapsed)))
            }
            Err(err) => Ok(Some((Err(err), elapsed))),
        }
    }

    /// Restore dirty windows consumed by a failed query so they are retried on
    /// the next execution.
    ///
    pub fn restore_dirty_windows(&self, dirty_restore: &DirtyRestore) {
        match dirty_restore {
            DirtyRestore::Scoped(filter) => self.restore_scoped_dirty_windows(filter),
            DirtyRestore::Unscoped(dirty_windows) => self
                .state
                .write()
                .unwrap()
                .dirty_time_windows
                .add_dirty_windows(dirty_windows),
        }
    }

    /// Restore the dirty signal for a plan that was generated but failed before
    /// it could prove any checkpoint advancement.
    fn restore_dirty_windows_after_failure(&self, query: &PlanInfo) {
        self.restore_dirty_windows(&query.dirty_restore);
    }

    /// Restore scoped windows through `TaskState` so fenced repair can decide
    /// whether they go back to pending repair or live dirty state.
    fn restore_scoped_dirty_windows(&self, filter: &FilterExprInfo) {
        self.state.write().unwrap().restore_scoped_windows(filter);
    }

    /// Run a fallible scoped operation and restore its consumed windows if plan
    /// generation/rewrite fails before execution.
    fn restore_scoped_dirty_windows_on_err<T>(
        &self,
        filter: &FilterExprInfo,
        result: Result<T, Error>,
    ) -> Result<T, Error> {
        result.inspect_err(|_| {
            self.restore_scoped_dirty_windows(filter);
        })
    }

    /// Restore an unscoped dirty signal consumed by an explicit full-query or
    /// incremental-delta plan.
    fn restore_unscoped_dirty_windows(&self, dirty_windows: &DirtyTimeWindows) {
        self.state
            .write()
            .unwrap()
            .dirty_time_windows
            .add_dirty_windows(dirty_windows);
    }

    /// Run a fallible unscoped operation and restore the dirty signal if it
    /// fails before a query is executed.
    fn restore_unscoped_dirty_windows_on_err<T>(
        &self,
        dirty_windows: &DirtyTimeWindows,
        result: Result<T, Error>,
    ) -> Result<T, Error> {
        result.inspect_err(|_| {
            self.restore_unscoped_dirty_windows(dirty_windows);
        })
    }

    /// Consume the live dirty signal for an unscoped query while keeping a copy
    /// that can be restored if planning or execution fails.
    fn drain_dirty_windows_signal(&self) -> (bool, DirtyTimeWindows) {
        let mut state = self.state.write().unwrap();
        let dirty_windows_to_restore = state.dirty_time_windows.clone();
        let is_dirty = !dirty_windows_to_restore.is_empty();
        state.dirty_time_windows.clean();
        (is_dirty, dirty_windows_to_restore)
    }

    #[allow(clippy::too_many_arguments)]
    /// Build an unfiltered plan for explicit full-query or incremental-delta
    /// coverage. Callers pass the consumed dirty signal for failure restoration.
    async fn gen_unfiltered_plan_info(
        &self,
        engine: QueryEngineRef,
        query_ctx: QueryContextRef,
        sink_table_schema: Arc<Schema>,
        primary_key_indices: &[usize],
        allow_partial: bool,
        values: &BTreeMap<String, ScalarValue>,
        dirty_windows_to_restore: DirtyTimeWindows,
        retention_filter: Option<(&str, Timestamp, &'static str)>,
        coverage: QueryCoverage,
    ) -> Result<PlanInfo, Error> {
        let mut plan = self.restore_unscoped_dirty_windows_on_err(
            &dirty_windows_to_restore,
            gen_plan_with_matching_schema_and_values(
                &self.config.query,
                query_ctx,
                engine,
                sink_table_schema,
                primary_key_indices,
                allow_partial,
                values,
            )
            .await,
        )?;

        if let Some((col_name, lower_bound, context)) = retention_filter {
            let lower = self.restore_unscoped_dirty_windows_on_err(
                &dirty_windows_to_restore,
                to_df_literal(lower_bound),
            )?;
            let retention_filter = col(col_name).gt_eq(lit(lower));
            let mut add_filter = AddFilterRewriter::new(retention_filter);
            plan = self.restore_unscoped_dirty_windows_on_err(
                &dirty_windows_to_restore,
                plan.clone()
                    .rewrite(&mut add_filter)
                    .with_context(|_| DatafusionSnafu {
                        context: format!(
                            "Failed to apply {context} expire_after filter to plan:\n {}\n",
                            plan
                        ),
                    })
                    .map(|rewrite| rewrite.data),
            )?;
        }

        Ok(PlanInfo {
            plan,
            dirty_restore: DirtyRestore::Unscoped(dirty_windows_to_restore),
            coverage,
        })
    }

    #[allow(clippy::too_many_arguments)]
    /// Build an unfiltered plan only when the live dirty signal was present;
    /// otherwise skip this round without querying.
    async fn gen_unfiltered_plan_info_if_dirty(
        &self,
        engine: QueryEngineRef,
        query_ctx: QueryContextRef,
        sink_table_schema: Arc<Schema>,
        primary_key_indices: &[usize],
        allow_partial: bool,
        values: &BTreeMap<String, ScalarValue>,
        retention_filter: Option<(&str, Timestamp, &'static str)>,
        coverage: QueryCoverage,
    ) -> Result<Option<PlanInfo>, Error> {
        let (is_dirty, dirty_windows_to_restore) = self.drain_dirty_windows_signal();
        if !is_dirty {
            debug!("Flow id={:?}, no new data, not update", self.config.flow_id);
            return Ok(None);
        }

        self.gen_unfiltered_plan_info(
            engine,
            query_ctx,
            sink_table_schema,
            primary_key_indices,
            allow_partial,
            values,
            dirty_windows_to_restore,
            retention_filter,
            coverage,
        )
        .await
        .map(Some)
    }

    fn handle_executed_query_failure(&self, query: Option<&PlanInfo>) {
        if let Some(query) = query {
            self.restore_dirty_windows_after_failure(query);
        }
    }

    /// start executing query in a loop, break when receive shutdown signal
    ///
    /// any error will be logged when executing query.
    ///
    /// Dispatches to:
    /// - scheduled loop when `flow_eval_interval.is_some()`
    /// - adaptive dirty-window loop otherwise
    pub async fn start_executing_loop(
        &self,
        engine: QueryEngineRef,
        frontend_client: Arc<FrontendClient>,
    ) {
        if self.config.flow_eval_interval.is_some() {
            self.start_scheduled_loop(engine, frontend_client).await;
        } else {
            self.start_adaptive_loop(engine, frontend_client).await;
        }
    }

    /// Scheduled batching loop for flows with `EVAL INTERVAL`.
    ///
    /// Uses the pre-parsed `EvalSchedule` from `TaskConfig` and selects due
    /// scheduled times using bounded catch-up semantics. Each scheduled time is the
    /// scheduled evaluation time used as logical `now()` for that attempt.
    /// Each attempt temporarily sets `flow.scheduled_time_millis` on the
    /// task's `QueryContext` and executes under the existing `execution_lock`.
    /// After every attempt (success, no-op, or failure) the in-memory
    /// cursor advances.
    async fn start_scheduled_loop(
        &self,
        engine: QueryEngineRef,
        frontend_client: Arc<FrontendClient>,
    ) {
        let flow_id_str = self.config.flow_id.to_string();

        let schedule = match &self.config.eval_schedule {
            Some(s) => s.clone(),
            None => {
                let eval_interval_secs = self
                    .config
                    .flow_eval_interval
                    .map(|d| d.as_secs() as i64)
                    .expect("checked by caller");

                // Fallback: no typed config provided. Compute defaults
                // anchored at epoch/start=0.
                match EvalSchedule::from_config(Some(eval_interval_secs), None) {
                    Ok(Some(s)) => s,
                    Ok(None) => {
                        warn!(
                            "Flow {}: EVAL INTERVAL set but no schedule parsed; exiting loop",
                            flow_id_str
                        );
                        return;
                    }
                    Err(e) => {
                        warn!(
                            "Flow {}: Failed to parse eval schedule: {}; exiting loop",
                            flow_id_str, e
                        );
                        return;
                    }
                }
            }
        };

        // Initial cursor is one interval before start so the first due
        // scheduled time is `start_secs`. An unrepresentable difference is an
        // explicit error, never a saturated cursor that would silently skip
        // the first scheduled tick.
        let mut cursor_secs =
            match initial_schedule_cursor(schedule.start_secs, schedule.interval_secs) {
                Ok(cursor) => cursor,
                Err(e) => {
                    warn!(
                        "Flow {}: invalid eval schedule, exiting loop: {}",
                        flow_id_str, e
                    );
                    return;
                }
            };

        info!(
            "Flow {}: entering scheduled loop, interval={}s, start={}, anchor={}, policy={:?}, max_runs={}, max_lag={}s",
            flow_id_str,
            schedule.interval_secs,
            schedule.start_secs,
            schedule.anchor_secs,
            schedule.missed_tick_policy,
            schedule.max_runs,
            schedule.max_lag_secs,
        );

        loop {
            if self.is_shutdown_signaled() {
                break;
            }

            let wall_now_secs = wall_clock_unix_secs();

            let due = match select_due_scheduled_times(&schedule, cursor_secs, wall_now_secs) {
                Ok(d) => d,
                Err(e) => {
                    warn!(
                        "Flow {}: invalid eval schedule, exiting loop: {}",
                        flow_id_str, e
                    );
                    return;
                }
            };

            if due.scheduled_times_secs.is_empty() {
                if due.skipped > 0 {
                    warn!(
                        "Flow {}: all {} due scheduled times skipped by max-lag, advancing cursor to wall-clock ({wall_now_secs}) to avoid re-skipping",
                        flow_id_str, due.skipped
                    );
                    cursor_secs = wall_now_secs;
                    continue;
                }

                // No due yet — sleep until the next scheduled time.
                let next = match schedule.next_scheduled_time_after(cursor_secs) {
                    Ok(next) => next,
                    Err(e) => {
                        warn!(
                            "Flow {}: cannot advance eval schedule past cursor {cursor_secs}: {e}; exiting loop",
                            flow_id_str
                        );
                        return;
                    }
                };
                if next <= wall_now_secs {
                    // Shouldn't happen given select_due_scheduled_times returned empty,
                    // but guard against clock skew / logic error.
                    cursor_secs = wall_now_secs;
                    continue;
                }
                let wait_secs = match sleep_delta_secs(next, wall_now_secs) {
                    Ok(wait_secs) => wait_secs,
                    Err(e) => {
                        warn!(
                            "Flow {}: cannot sleep until next scheduled time {}: {e}; exiting loop",
                            flow_id_str, next
                        );
                        return;
                    }
                };
                let wait_dur = Duration::from_secs(wait_secs);
                debug!(
                    "Flow {}: no due scheduled times, sleeping for {}s until next scheduled time at {}",
                    flow_id_str, wait_secs, next
                );
                tokio::time::sleep(wait_dur).await;
                continue;
            }

            if due.skipped > 0 {
                info!(
                    "Flow {}: {} due scheduled times, {} skipped (catch-up)",
                    flow_id_str,
                    due.scheduled_times_secs.len(),
                    due.skipped
                );
            }

            // Execute scheduled times oldest → newest.
            for scheduled_time_secs in &due.scheduled_times_secs {
                if self.is_shutdown_signaled() {
                    break;
                }

                METRIC_FLOW_BATCHING_ENGINE_START_QUERY_CNT
                    .with_label_values(&[&flow_id_str])
                    .inc();

                let outcome = self
                    .execute_once_serialized_at_scheduled_time(
                        &engine,
                        &frontend_client,
                        *scheduled_time_secs,
                    )
                    .await;

                // Advance cursor regardless of outcome.
                cursor_secs = *scheduled_time_secs;

                match outcome.result {
                    Ok(Some((rows, elapsed))) => {
                        debug!(
                            "Flow {}: scheduled time {} completed, rows={}, elapsed={:?}",
                            flow_id_str, scheduled_time_secs, rows, elapsed
                        );
                    }
                    Ok(None) => {
                        debug!(
                            "Flow {}: scheduled time {} produced no query (no dirty signal or no-op)",
                            flow_id_str, scheduled_time_secs
                        );
                    }
                    Err(err) => {
                        warn!(
                            "Flow {}: scheduled time {} failed: {:?}",
                            flow_id_str, scheduled_time_secs, err
                        );
                        METRIC_FLOW_BATCHING_ENGINE_ERROR_CNT
                            .with_label_values(&[&flow_id_str])
                            .inc();
                        // Dirty-window restoration is handled by the
                        // existing `handle_executed_query_failure` inside
                        // default execution.
                    }
                }
            }
        }
    }

    /// Existing adaptive dirty-window loop for flows without `EVAL INTERVAL`.
    async fn start_adaptive_loop(
        &self,
        engine: QueryEngineRef,
        frontend_client: Arc<FrontendClient>,
    ) {
        let flow_id_str = self.config.flow_id.to_string();
        let mut max_window_cnt = None;
        loop {
            if self.is_shutdown_signaled() {
                break;
            }
            METRIC_FLOW_BATCHING_ENGINE_START_QUERY_CNT
                .with_label_values(&[&flow_id_str])
                .inc();

            let min_refresh = self.config.batch_opts.experimental_min_refresh_duration;

            let outcome = self
                .execute_once_serialized_with_outcome(&engine, &frontend_client, max_window_cnt)
                .await;

            match outcome.result {
                Ok(Some(_)) => {
                    max_window_cnt = max_window_cnt.map(|cnt| {
                        (cnt + 1).min(self.config.batch_opts.experimental_max_filter_num_per_query)
                    });

                    let sleep_until = {
                        let state = self.state.write().unwrap();

                        let time_window_size = self
                            .config
                            .time_window_expr
                            .as_ref()
                            .and_then(|t| *t.time_window_size());

                        let prefer_short_incremental_cadence = state.checkpoint_mode()
                            == CheckpointMode::Incremental
                            && !state.is_incremental_disabled();

                        state.get_next_start_query_time(
                            self.config.flow_id,
                            &time_window_size,
                            min_refresh,
                            Some(self.config.batch_opts.query_timeout),
                            self.config.batch_opts.experimental_max_filter_num_per_query,
                            prefer_short_incremental_cadence,
                        )
                    };

                    tokio::time::sleep_until(sleep_until).await;
                }
                Ok(None) => {
                    debug!(
                        "Flow id = {:?} found no new data, sleep for {:?} then continue",
                        self.config.flow_id, min_refresh
                    );
                    tokio::time::sleep(min_refresh).await;
                    continue;
                }
                Err(err) => {
                    METRIC_FLOW_BATCHING_ENGINE_ERROR_CNT
                        .with_label_values(&[&flow_id_str])
                        .inc();
                    match outcome.new_query {
                        Some(query) => {
                            common_telemetry::error!(err; "Failed to execute query for flow={} with query: {}", self.config.flow_id, query.plan);
                            max_window_cnt = Some(1);
                        }
                        None => {
                            common_telemetry::error!(err; "Failed to generate query for flow={}", self.config.flow_id)
                        }
                    }
                    tokio::time::sleep(min_refresh).await;
                }
            }
        }
    }

    /// Check whether the shutdown signal has been received.
    fn is_shutdown_signaled(&self) -> bool {
        let mut state = self.state.write().unwrap();
        match state.shutdown_rx.try_recv() {
            Ok(()) | Err(TryRecvError::Closed) => true,
            Err(TryRecvError::Empty) => false,
        }
    }

    /// Execute one scheduled attempt, temporarily setting
    /// `flow.scheduled_time_millis` on the task's QueryContext so
    /// SQL/TQL `now()` resolves to the logical scheduled time.
    ///
    /// The extension is removed after the attempt so a later manual
    /// `flush_flow` does not reuse a stale scheduled time.
    async fn execute_once_serialized_at_scheduled_time(
        &self,
        engine: &QueryEngineRef,
        frontend_client: &Arc<FrontendClient>,
        scheduled_time_secs: i64,
    ) -> ExecuteOnceOutcome {
        let mut guard = BatchingExecutionGuard::new(self.execution_lock.clone().lock_owned().await);

        // Convert to milliseconds before touching the task state so an
        // unrepresentable scheduled time fails as an explicit error without
        // ever installing a saturated (off-phase) extension value.
        let scheduled_time_millis = match scheduled_time_millis(scheduled_time_secs) {
            Ok(millis) => millis,
            Err(e) => {
                return ExecuteOnceOutcome {
                    new_query: None,
                    result: Err(e),
                };
            }
        };

        // Clone the current QueryContext and add the scheduled time
        // extension, then swap it into the task state for this attempt.
        let old_ctx = {
            let mut state = self.state.write().unwrap();
            let old = state.query_ctx.clone();
            let mut new_ctx = (*old).clone();
            new_ctx.set_extension(
                query::options::FLOW_SCHEDULED_TIME_MILLIS,
                scheduled_time_millis.to_string(),
            );
            state.query_ctx = Arc::new(new_ctx);
            old
        };
        guard.restore_query_context(self.state.clone(), old_ctx);

        // A collaborator may retain the guard in an owned child task. Its Drop
        // restores the scheduled context before releasing serialization.
        self.execute_once_with_guard(guard, engine, frontend_client, None)
            .await
    }

    /// Generate the create table SQL
    ///
    /// the auto created table will automatically added a `update_at` Milliseconds DEFAULT now() column in the end
    /// (for compatibility with flow streaming mode)
    ///
    /// and it will use first timestamp column as time index, all other columns will be added as normal columns and nullable
    async fn gen_create_table_expr(
        &self,
        engine: QueryEngineRef,
    ) -> Result<CreateTableExpr, Error> {
        let query_ctx = self.state.read().unwrap().query_ctx.clone();
        let plan =
            sql_to_df_plan(query_ctx.clone(), engine.clone(), &self.config.query, true).await?;
        create_table_with_expr(&plan, &self.config.sink_table_name, &self.config.query_type)
    }

    /// Incremental delta scans are unfiltered by dirty windows; the sequence
    /// range, not a time predicate, defines source correctness.
    fn should_use_unfiltered_incremental_delta(&self) -> bool {
        let state = self.state.read().unwrap();
        state.checkpoint_mode() == CheckpointMode::Incremental
            && !state.is_incremental_disabled()
            && matches!(self.config.query_type, QueryType::Sql)
    }

    /// Generate the next ordinary plan and classify its coverage.
    async fn gen_query_with_time_window(
        &self,
        engine: QueryEngineRef,
        sink_table_schema: &Arc<Schema>,
        primary_key_indices: &[usize],
        allow_partial: bool,
        max_window_cnt: Option<usize>,
    ) -> Result<Option<PlanInfo>, Error> {
        self.gen_query_with_time_window_with_values(
            engine,
            sink_table_schema,
            primary_key_indices,
            allow_partial,
            max_window_cnt,
            &BTreeMap::new(),
            false,
        )
        .await
    }

    /// Generate the next plan with extension-owned sink values and an optional forced full scan.
    #[allow(clippy::too_many_arguments)]
    async fn gen_query_with_time_window_with_values(
        &self,
        engine: QueryEngineRef,
        sink_table_schema: &Arc<Schema>,
        primary_key_indices: &[usize],
        allow_partial: bool,
        max_window_cnt: Option<usize>,
        values: &BTreeMap<String, ScalarValue>,
        force_full_snapshot: bool,
    ) -> Result<Option<PlanInfo>, Error> {
        let query_ctx = self.state.read().unwrap().query_ctx.clone();
        let start = SystemTime::now();
        let since_the_epoch = start
            .duration_since(UNIX_EPOCH)
            .expect("Time went backwards");
        let low_bound = self
            .config
            .expire_after
            .map(|e| since_the_epoch.as_secs() - e as u64)
            .unwrap_or(u64::MIN);

        let low_bound = Timestamp::new_second(low_bound as i64);

        let expire_time_window_bound = self
            .config
            .time_window_expr
            .as_ref()
            .map(|expr| expr.eval(low_bound))
            .transpose()?;

        let (expire_lower_bound, expire_upper_bound) = match (
            expire_time_window_bound,
            &self.config.query_type,
        ) {
            (Some((Some(l), Some(u))), QueryType::Sql) => (l, u),
            (None, QueryType::Sql) if self.config.flow_eval_interval.is_none() => {
                return UnexpectedSnafu {
                    reason: format!(
                        "Flow id={} reached execution without a time-window expression or EVAL INTERVAL; create-flow validation should have rejected it",
                        self.config.flow_id
                    ),
                }
                .fail();
            }
            _ => {
                // Explicit full-query flows (TQL and evaluation-interval SQL
                // plans whose shape cannot be safely dirty-window pruned) are
                // allowed to run as unfiltered full snapshots. This is distinct
                // from using unfiltered full as a fallback after scoped repair or
                // incremental rewrite failed.
                let (_, dirty_windows_to_restore) = self.drain_dirty_windows_signal();

                let plan_info = self
                    .gen_unfiltered_plan_info(
                        engine,
                        query_ctx,
                        sink_table_schema.clone(),
                        primary_key_indices,
                        allow_partial,
                        values,
                        dirty_windows_to_restore,
                        None,
                        QueryCoverage::UnfilteredFull,
                    )
                    .await?;

                return Ok(Some(plan_info));
            }
        };

        debug!(
            "Flow id = {:?}, found time window: precise_lower_bound={:?}, precise_upper_bound={:?} with dirty time windows: {:?}",
            self.config.flow_id,
            expire_lower_bound,
            expire_upper_bound,
            self.state.read().unwrap().dirty_time_windows
        );
        let window_size = expire_upper_bound
            .sub(&expire_lower_bound)
            .with_context(|| UnexpectedSnafu {
                reason: format!(
                    "Can't get window size from {expire_upper_bound:?} - {expire_lower_bound:?}"
                ),
            })?;
        let col_name = self
            .config
            .time_window_expr
            .as_ref()
            .map(|expr| expr.column_name.clone())
            .with_context(|| UnexpectedSnafu {
                reason: format!(
                    "Flow id={:?}, Failed to get column name from time window expr",
                    self.config.flow_id
                ),
            })?;

        if force_full_snapshot {
            // Durable execution cannot trust an uncertain prior checkpoint. Re-run an
            // unfiltered full snapshot, but retain the normal expiry predicate and the consumed
            // dirty signal so every planning/execution failure remains reversible.
            let retention_filter = self.config.expire_after.map(|_| {
                (
                    col_name.as_str(),
                    expire_lower_bound,
                    "forced full snapshot",
                )
            });
            let (_, dirty_windows_to_restore) = self.drain_dirty_windows_signal();
            return self
                .gen_unfiltered_plan_info(
                    engine,
                    query_ctx,
                    sink_table_schema.clone(),
                    primary_key_indices,
                    allow_partial,
                    values,
                    dirty_windows_to_restore,
                    retention_filter,
                    QueryCoverage::UnfilteredFull,
                )
                .await
                .map(Some);
        }

        if self.should_use_unfiltered_incremental_delta() {
            // In incremental mode, source correctness is defined by the
            // per-region sequence range `(checkpoint, scan-open snapshot]`, not
            // by dirty-window predicates. Dirty windows are only a scheduling
            // signal here. Applying a stale dirty-window filter to the source can
            // exclude rows that are inside the returned watermark and make a
            // checkpoint advance skip them forever. The sink side is also left
            // unfiltered by dirty windows; the incremental rewrite joins the
            // delta groups with the full sink state for correctness. Future
            // dynamic filters can prune sink reads as a pure optimization.
            let retention_filter = self
                .config
                .expire_after
                .map(|_| (col_name.as_str(), expire_lower_bound, "incremental"));
            return self
                .gen_unfiltered_plan_info_if_dirty(
                    engine,
                    query_ctx,
                    sink_table_schema.clone(),
                    primary_key_indices,
                    allow_partial,
                    values,
                    retention_filter,
                    QueryCoverage::IncrementalDelta,
                )
                .await;
        }

        let (expr, coverage) = {
            let mut state = self.state.write().unwrap();
            let window_cnt = max_window_cnt
                .unwrap_or(self.config.batch_opts.experimental_max_filter_num_per_query);
            let expr = state.gen_scoped_filter_exprs(
                &col_name,
                Some(expire_lower_bound),
                window_size,
                window_cnt,
                self.config.flow_id,
                Some(self),
            )?;
            let repair_high = state
                .pending_fenced_repair()
                .map(|repair| repair.high().clone());
            let coverage = if let Some(high) = repair_high {
                QueryCoverage::FencedRepairChunk { high }
            } else {
                QueryCoverage::ScopedBaseRepair
            };
            (expr, coverage)
        };

        let Some(expr) = expr else {
            // no new data, hence no need to update
            debug!("Flow id={:?}, no new data, not update", self.config.flow_id);
            return Ok(None);
        };

        let filter_sql = expr_to_sql(&expr.expr)
            .map(|sql| sql.to_string())
            .unwrap_or_else(|err| format!("<failed to format filter expr: {err}>"));

        debug!(
            "Flow id={:?}, Generated filter expr: {:?}",
            self.config.flow_id, filter_sql
        );

        let mut add_filter = AddFilterRewriter::new(expr.expr.clone());
        let mut add_auto_column = ColumnMatcherRewriter::new_with_values(
            sink_table_schema.clone(),
            primary_key_indices.to_vec(),
            allow_partial,
            values.clone(),
        );

        let plan = self.restore_scoped_dirty_windows_on_err(
            &expr,
            sql_to_df_plan(query_ctx.clone(), engine.clone(), &self.config.query, false).await,
        )?;
        let rewrite = self.restore_scoped_dirty_windows_on_err(
            &expr,
            plan.clone()
                .rewrite(&mut add_filter)
                .and_then(|p| p.data.rewrite(&mut add_auto_column))
                .with_context(|_| DatafusionSnafu {
                    context: format!("Failed to rewrite plan:\n {}\n", plan),
                })
                .map(|rewrite| rewrite.data),
        )?;
        // only apply optimize after complex rewrite is done
        let new_plan = self.restore_scoped_dirty_windows_on_err(
            &expr,
            apply_df_optimizer(rewrite, &query_ctx).await,
        )?;

        let info = PlanInfo {
            plan: new_plan.clone(),
            dirty_restore: DirtyRestore::Scoped(expr),
            coverage,
        };

        Ok(Some(info))
    }
}

#[cfg(test)]
mod test;