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icydb_core/db/executor/explain/
mod.rs

1//! Module: db::executor::explain
2//! Responsibility: assemble executor-owned EXPLAIN descriptor payloads.
3//! Does not own: explain rendering formats or logical plan projection.
4//! Boundary: centralized execution-plan-to-descriptor mapping used by EXPLAIN surfaces.
5
6mod descriptor;
7
8#[cfg(test)]
9use crate::db::executor::planning::route::AggregateRouteShape;
10#[cfg(test)]
11use crate::db::query::builder::AggregateExpr;
12use crate::{
13    db::{
14        Query, TraceReuseEvent,
15        executor::{BytesByProjectionMode, EntityAuthority, PreparedExecutionPlan},
16        predicate::{CoercionId, CompareOp},
17        query::{
18            builder::{AggregateExplain, ProjectionExplain},
19            explain::{
20                ExplainAccessPath, ExplainAggregateTerminalPlan, ExplainExecutionNodeDescriptor,
21                ExplainExecutionNodeType, ExplainOrderPushdown, ExplainPredicate,
22                FinalizedQueryDiagnostics,
23            },
24            intent::{QueryError, StructuralQuery},
25            plan::{AccessPlannedQuery, VisibleIndexes, explain_access_kind_label},
26        },
27    },
28    traits::{EntityKind, EntityValue},
29    value::Value,
30};
31
32#[cfg(test)]
33pub(in crate::db) use descriptor::assemble_load_execution_node_descriptor;
34use descriptor::assemble_load_execution_verbose_diagnostics_from_route_facts;
35pub(in crate::db) use descriptor::{
36    assemble_aggregate_terminal_execution_descriptor,
37    assemble_load_execution_node_descriptor_for_authority,
38    assemble_load_execution_node_descriptor_from_route_facts,
39    assemble_scalar_aggregate_execution_descriptor_with_projection,
40    freeze_load_execution_route_facts_for_authority,
41    freeze_load_execution_route_facts_for_model_only,
42};
43
44impl StructuralQuery {
45    // Assemble one finalized diagnostics artifact from route facts that were
46    // already frozen by the caller-selected schema authority.
47    fn finalized_execution_diagnostics_from_route_facts(
48        plan: &AccessPlannedQuery,
49        route_facts: &crate::db::executor::explain::descriptor::LoadExecutionRouteFacts,
50        reuse: Option<TraceReuseEvent>,
51    ) -> FinalizedQueryDiagnostics {
52        let descriptor =
53            assemble_load_execution_node_descriptor_from_route_facts(plan, route_facts);
54        let route_diagnostics =
55            assemble_load_execution_verbose_diagnostics_from_route_facts(plan, route_facts);
56        let explain = plan.explain();
57
58        // Phase 1: add descriptor-stage summaries for key execution operators.
59        let mut logical_diagnostics = Vec::new();
60        logical_diagnostics.push(format!(
61            "diag.d.has_top_n_seek={}",
62            descriptor.contains_type(ExplainExecutionNodeType::TopNSeek)
63        ));
64        logical_diagnostics.push(format!(
65            "diag.d.has_index_range_limit_pushdown={}",
66            descriptor.contains_type(ExplainExecutionNodeType::IndexRangeLimitPushdown)
67        ));
68        logical_diagnostics.push(format!(
69            "diag.d.has_index_predicate_prefilter={}",
70            descriptor.contains_type(ExplainExecutionNodeType::IndexPredicatePrefilter)
71        ));
72        logical_diagnostics.push(format!(
73            "diag.d.has_residual_filter={}",
74            descriptor.contains_type(ExplainExecutionNodeType::ResidualFilter)
75        ));
76
77        // Phase 2: append logical-plan diagnostics relevant to verbose explain.
78        logical_diagnostics.push(format!("diag.p.mode={:?}", explain.mode()));
79        logical_diagnostics.push(format!(
80            "diag.p.order_pushdown={}",
81            plan_order_pushdown_label(explain.order_pushdown())
82        ));
83        logical_diagnostics.push(format!(
84            "diag.p.predicate_pushdown={}",
85            plan_predicate_pushdown_label(explain.predicate(), explain.access())
86        ));
87        logical_diagnostics.push(format!("diag.p.distinct={}", explain.distinct()));
88        logical_diagnostics.push(format!("diag.p.page={:?}", explain.page()));
89        logical_diagnostics.push(format!("diag.p.consistency={:?}", explain.consistency()));
90
91        FinalizedQueryDiagnostics::new(descriptor, route_diagnostics, logical_diagnostics, reuse)
92    }
93
94    // Assemble one model-only execution descriptor from a previously built
95    // access plan so standalone text/json/verbose explain surfaces do not each
96    // rebuild it.
97    pub(in crate::db) fn explain_execution_descriptor_from_model_only_plan(
98        &self,
99        plan: &AccessPlannedQuery,
100    ) -> Result<ExplainExecutionNodeDescriptor, QueryError> {
101        let route_facts = freeze_load_execution_route_facts_for_model_only(
102            self.model().fields(),
103            self.model().primary_key().name(),
104            plan,
105        )
106        .map_err(QueryError::execute)?;
107
108        Ok(assemble_load_execution_node_descriptor_from_route_facts(
109            plan,
110            &route_facts,
111        ))
112    }
113
114    // Assemble one execution descriptor from accepted executor authority.
115    pub(in crate::db) fn explain_execution_descriptor_from_plan_with_authority(
116        &self,
117        plan: &AccessPlannedQuery,
118        authority: &EntityAuthority,
119    ) -> Result<ExplainExecutionNodeDescriptor, QueryError> {
120        debug_assert_eq!(self.model().path(), authority.entity_path());
121        let route_facts = freeze_load_execution_route_facts_for_authority(authority, plan)
122            .map_err(QueryError::execute)?;
123
124        Ok(assemble_load_execution_node_descriptor_from_route_facts(
125            plan,
126            &route_facts,
127        ))
128    }
129
130    // Render one standalone model-only verbose execution explain payload from
131    // a single access plan, freezing one immutable diagnostics artifact instead
132    // of returning one wrapper-owned line list that callers still have to
133    // extend locally.
134    fn finalized_execution_diagnostics_from_model_only_plan(
135        &self,
136        plan: &AccessPlannedQuery,
137        reuse: Option<TraceReuseEvent>,
138    ) -> Result<FinalizedQueryDiagnostics, QueryError> {
139        let route_facts = freeze_load_execution_route_facts_for_model_only(
140            self.model().fields(),
141            self.model().primary_key().name(),
142            plan,
143        )
144        .map_err(QueryError::execute)?;
145
146        Ok(Self::finalized_execution_diagnostics_from_route_facts(
147            plan,
148            &route_facts,
149            reuse,
150        ))
151    }
152
153    /// Freeze one immutable diagnostics artifact through accepted executor
154    /// authority while still allowing one caller-owned descriptor mutation.
155    pub(in crate::db) fn finalized_execution_diagnostics_from_plan_with_authority_and_descriptor_mutator(
156        &self,
157        plan: &AccessPlannedQuery,
158        authority: &EntityAuthority,
159        reuse: Option<TraceReuseEvent>,
160        mutate_descriptor: impl FnOnce(&mut ExplainExecutionNodeDescriptor),
161    ) -> Result<FinalizedQueryDiagnostics, QueryError> {
162        debug_assert_eq!(self.model().path(), authority.entity_path());
163        let route_facts = freeze_load_execution_route_facts_for_authority(authority, plan)
164            .map_err(QueryError::execute)?;
165        let mut diagnostics =
166            Self::finalized_execution_diagnostics_from_route_facts(plan, &route_facts, reuse);
167        mutate_descriptor(&mut diagnostics.execution);
168
169        Ok(diagnostics)
170    }
171
172    // Render one verbose execution explain payload using only the canonical
173    // diagnostics artifact owned by this executor boundary.
174    fn explain_execution_verbose_from_plan(
175        &self,
176        plan: &AccessPlannedQuery,
177    ) -> Result<String, QueryError> {
178        self.finalized_execution_diagnostics_from_model_only_plan(plan, None)
179            .map(|diagnostics| diagnostics.render_text_verbose())
180    }
181
182    // Freeze one explain-only access-choice snapshot from accepted
183    // planner-visible indexes before building descriptor diagnostics.
184    fn finalize_explain_access_choice_for_visible_indexes(
185        &self,
186        plan: &mut AccessPlannedQuery,
187        visible_indexes: &VisibleIndexes<'_>,
188    ) {
189        if let Some(schema_info) = visible_indexes.accepted_schema_info() {
190            plan.finalize_access_choice_for_model_with_accepted_indexes_and_schema(
191                self.model(),
192                visible_indexes.as_slice(),
193                visible_indexes.accepted_field_path_indexes(),
194                schema_info,
195            );
196            return;
197        }
198
199        plan.finalize_access_choice_for_model_only_with_indexes(
200            self.model(),
201            visible_indexes.as_slice(),
202        );
203    }
204
205    // Freeze one explicit model-only access-choice snapshot for standalone
206    // query explain surfaces that intentionally do not have accepted runtime
207    // schema authority.
208    fn finalize_explain_access_choice_for_model_only(&self, plan: &mut AccessPlannedQuery) {
209        plan.finalize_access_choice_for_model_only_with_indexes(
210            self.model(),
211            self.model().indexes(),
212        );
213    }
214
215    // Build one explicit model-only execution descriptor for standalone query
216    // surfaces that are not bound to a recovered store/accepted schema.
217    fn explain_execution_descriptor_for_model_only(
218        &self,
219    ) -> Result<ExplainExecutionNodeDescriptor, QueryError> {
220        let mut plan = self.build_plan()?;
221        self.finalize_explain_access_choice_for_model_only(&mut plan);
222
223        self.explain_execution_descriptor_from_model_only_plan(&plan)
224    }
225
226    // Build one execution descriptor using the caller-resolved accepted visible
227    // indexes for runtime/session explain.
228    fn explain_execution_descriptor_for_visible_indexes(
229        &self,
230        visible_indexes: &VisibleIndexes<'_>,
231    ) -> Result<ExplainExecutionNodeDescriptor, QueryError> {
232        let mut plan = self.build_plan_with_visible_indexes(visible_indexes)?;
233        self.finalize_explain_access_choice_for_visible_indexes(&mut plan, visible_indexes);
234
235        self.explain_execution_descriptor_from_model_only_plan(&plan)
236    }
237
238    // Render one explicit model-only verbose execution payload for standalone
239    // query surfaces that are not bound to a recovered store/accepted schema.
240    fn render_execution_verbose_for_model_only(&self) -> Result<String, QueryError> {
241        let mut plan = self.build_plan()?;
242        self.finalize_explain_access_choice_for_model_only(&mut plan);
243
244        self.explain_execution_verbose_from_plan(&plan)
245    }
246
247    // Render one verbose execution payload using the caller-resolved accepted
248    // visible indexes for runtime/session explain.
249    fn explain_execution_verbose_for_visible_indexes(
250        &self,
251        visible_indexes: &VisibleIndexes<'_>,
252    ) -> Result<String, QueryError> {
253        let mut plan = self.build_plan_with_visible_indexes(visible_indexes)?;
254        self.finalize_explain_access_choice_for_visible_indexes(&mut plan, visible_indexes);
255
256        self.explain_execution_verbose_from_plan(&plan)
257    }
258
259    /// Explain one model-only load execution shape through the structural query core.
260    #[inline(never)]
261    pub(in crate::db) fn explain_execution_for_model_only(
262        &self,
263    ) -> Result<ExplainExecutionNodeDescriptor, QueryError> {
264        self.explain_execution_descriptor_for_model_only()
265    }
266
267    /// Explain one load execution shape using a caller-visible index slice.
268    #[inline(never)]
269    pub(in crate::db) fn explain_execution_with_visible_indexes(
270        &self,
271        visible_indexes: &VisibleIndexes<'_>,
272    ) -> Result<ExplainExecutionNodeDescriptor, QueryError> {
273        self.explain_execution_descriptor_for_visible_indexes(visible_indexes)
274    }
275
276    /// Render one model-only verbose scalar load execution payload through the
277    /// shared structural descriptor and route-diagnostics paths.
278    #[inline(never)]
279    pub(in crate::db) fn explain_execution_verbose_for_model_only(
280        &self,
281    ) -> Result<String, QueryError> {
282        self.render_execution_verbose_for_model_only()
283    }
284
285    /// Render one verbose scalar load execution payload using visible indexes.
286    #[inline(never)]
287    pub(in crate::db) fn explain_execution_verbose_with_visible_indexes(
288        &self,
289        visible_indexes: &VisibleIndexes<'_>,
290    ) -> Result<String, QueryError> {
291        self.explain_execution_verbose_for_visible_indexes(visible_indexes)
292    }
293
294    /// Explain one aggregate terminal execution route without running it.
295    #[inline(never)]
296    #[cfg(test)]
297    pub(in crate::db) fn explain_aggregate_terminal_with_visible_indexes(
298        &self,
299        visible_indexes: &VisibleIndexes<'_>,
300        aggregate: AggregateRouteShape<'_>,
301    ) -> Result<ExplainAggregateTerminalPlan, QueryError> {
302        let plan = self.build_plan_with_visible_indexes(visible_indexes)?;
303        let query_explain = plan.explain();
304        let terminal = aggregate.kind();
305        let execution = assemble_aggregate_terminal_execution_descriptor(&plan, aggregate);
306
307        Ok(ExplainAggregateTerminalPlan::new(
308            query_explain,
309            terminal,
310            execution,
311        ))
312    }
313}
314
315impl<E> PreparedExecutionPlan<E>
316where
317    E: EntityValue + EntityKind,
318{
319    /// Explain one cached prepared aggregate terminal route without running it.
320    pub(in crate::db) fn explain_prepared_aggregate_terminal<S>(
321        &self,
322        strategy: &S,
323    ) -> Result<ExplainAggregateTerminalPlan, QueryError>
324    where
325        S: AggregateExplain,
326    {
327        let Some(kind) = strategy.explain_aggregate_kind() else {
328            return Err(QueryError::invariant(
329                "prepared fluent aggregate explain requires an explain-visible aggregate kind",
330            ));
331        };
332        let aggregate = self
333            .authority()
334            .aggregate_route_shape(kind, strategy.explain_projected_field())
335            .map_err(QueryError::execute)?;
336        let execution =
337            assemble_aggregate_terminal_execution_descriptor(self.logical_plan(), aggregate);
338
339        Ok(ExplainAggregateTerminalPlan::new(
340            self.logical_plan().explain(),
341            kind,
342            execution,
343        ))
344    }
345
346    /// Explain one cached prepared `bytes_by(field)` terminal route without running it.
347    pub(in crate::db) fn explain_bytes_by_terminal(
348        &self,
349        target_field: &str,
350    ) -> Result<ExplainExecutionNodeDescriptor, QueryError> {
351        let mut descriptor = self
352            .explain_load_execution_node_descriptor()
353            .map_err(QueryError::execute)?;
354        let projection_mode = self.bytes_by_projection_mode(target_field);
355        let projection_mode_label = Self::bytes_by_projection_mode_label(projection_mode);
356
357        descriptor
358            .node_properties
359            .insert("terminal", Value::from("bytes_by"));
360        descriptor
361            .node_properties
362            .insert("terminal_field", Value::from(target_field.to_string()));
363        descriptor.node_properties.insert(
364            "terminal_projection_mode",
365            Value::from(projection_mode_label),
366        );
367        descriptor.node_properties.insert(
368            "terminal_index_only",
369            Value::from(matches!(
370                projection_mode,
371                BytesByProjectionMode::CoveringIndex | BytesByProjectionMode::CoveringConstant
372            )),
373        );
374
375        Ok(descriptor)
376    }
377
378    /// Explain one cached prepared projection terminal route without running it.
379    pub(in crate::db) fn explain_prepared_projection_terminal<S>(
380        &self,
381        strategy: &S,
382    ) -> Result<ExplainExecutionNodeDescriptor, QueryError>
383    where
384        S: ProjectionExplain,
385    {
386        let mut descriptor = self
387            .explain_load_execution_node_descriptor()
388            .map_err(QueryError::execute)?;
389        let projection_descriptor = strategy.explain_projection_descriptor();
390
391        descriptor.node_properties.insert(
392            "terminal",
393            Value::from(projection_descriptor.terminal_label()),
394        );
395        descriptor.node_properties.insert(
396            "terminal_field",
397            Value::from(projection_descriptor.field_label().to_string()),
398        );
399        descriptor.node_properties.insert(
400            "terminal_output",
401            Value::from(projection_descriptor.output_label()),
402        );
403
404        Ok(descriptor)
405    }
406}
407
408impl<E> Query<E>
409where
410    E: EntityValue + EntityKind,
411{
412    // Resolve the structural execution descriptor through either the explicit
413    // model-only lane or one caller-provided visible-index slice.
414    fn explain_execution_descriptor_for_model_only_or_visible_indexes(
415        &self,
416        visible_indexes: Option<&VisibleIndexes<'_>>,
417    ) -> Result<ExplainExecutionNodeDescriptor, QueryError> {
418        match visible_indexes {
419            Some(visible_indexes) => self
420                .structural()
421                .explain_execution_with_visible_indexes(visible_indexes),
422            None => self.structural().explain_execution_for_model_only(),
423        }
424    }
425
426    // Render one descriptor-derived execution surface after resolving the
427    // visibility slice once at the typed query boundary.
428    fn render_execution_descriptor_for_visibility(
429        &self,
430        visible_indexes: Option<&VisibleIndexes<'_>>,
431        render: impl FnOnce(ExplainExecutionNodeDescriptor) -> String,
432    ) -> Result<String, QueryError> {
433        let descriptor =
434            self.explain_execution_descriptor_for_model_only_or_visible_indexes(visible_indexes)?;
435
436        Ok(render(descriptor))
437    }
438
439    // Render one verbose execution explain payload after choosing the explicit
440    // model-only lane or the accepted visible-index lane once.
441    fn explain_execution_verbose_for_model_only_or_visible_indexes(
442        &self,
443        visible_indexes: Option<&VisibleIndexes<'_>>,
444    ) -> Result<String, QueryError> {
445        match visible_indexes {
446            Some(visible_indexes) => self
447                .structural()
448                .explain_execution_verbose_with_visible_indexes(visible_indexes),
449            None => self.structural().explain_execution_verbose_for_model_only(),
450        }
451    }
452
453    /// Explain executor-selected load execution shape without running it.
454    pub fn explain_execution(&self) -> Result<ExplainExecutionNodeDescriptor, QueryError> {
455        self.explain_execution_descriptor_for_model_only_or_visible_indexes(None)
456    }
457
458    /// Explain executor-selected load execution shape with caller-visible indexes.
459    #[cfg(test)]
460    pub(in crate::db) fn explain_execution_with_visible_indexes(
461        &self,
462        visible_indexes: &VisibleIndexes<'_>,
463    ) -> Result<ExplainExecutionNodeDescriptor, QueryError> {
464        self.explain_execution_descriptor_for_model_only_or_visible_indexes(Some(visible_indexes))
465    }
466
467    /// Explain executor-selected load execution shape as deterministic text.
468    pub fn explain_execution_text(&self) -> Result<String, QueryError> {
469        self.render_execution_descriptor_for_visibility(None, |descriptor| {
470            descriptor.render_text_tree()
471        })
472    }
473
474    /// Explain executor-selected load execution shape as canonical JSON.
475    pub fn explain_execution_json(&self) -> Result<String, QueryError> {
476        self.render_execution_descriptor_for_visibility(None, |descriptor| {
477            descriptor.render_json_canonical()
478        })
479    }
480
481    /// Explain executor-selected load execution shape with route diagnostics.
482    #[inline(never)]
483    pub fn explain_execution_verbose(&self) -> Result<String, QueryError> {
484        self.explain_execution_verbose_for_model_only_or_visible_indexes(None)
485    }
486
487    /// Explain one aggregate terminal execution route without running it.
488    #[cfg(test)]
489    #[inline(never)]
490    pub(in crate::db) fn explain_aggregate_terminal(
491        &self,
492        aggregate: AggregateExpr,
493    ) -> Result<ExplainAggregateTerminalPlan, QueryError> {
494        self.structural()
495            .explain_aggregate_terminal_with_visible_indexes(
496                &VisibleIndexes::schema_owned(E::MODEL.indexes()),
497                AggregateRouteShape::new_from_fields(
498                    aggregate.kind(),
499                    aggregate.target_field(),
500                    E::MODEL.fields(),
501                    E::MODEL.primary_key().name(),
502                ),
503            )
504    }
505}
506
507// Render the logical ORDER pushdown label for verbose execution diagnostics.
508fn plan_order_pushdown_label(order_pushdown: &ExplainOrderPushdown) -> String {
509    match order_pushdown {
510        ExplainOrderPushdown::MissingModelContext => "missing_model_context".to_string(),
511        ExplainOrderPushdown::EligibleSecondaryIndex { index, prefix_len } => {
512            format!("eligible(index={index},prefix_len={prefix_len})")
513        }
514        ExplainOrderPushdown::Rejected(reason) => format!("rejected({reason:?})"),
515    }
516}
517
518// Render the logical predicate pushdown label for verbose execution diagnostics.
519fn plan_predicate_pushdown_label(
520    predicate: &ExplainPredicate,
521    access: &ExplainAccessPath,
522) -> String {
523    let access_label = explain_access_kind_label(access);
524    if matches!(predicate, ExplainPredicate::None) {
525        return "none".to_string();
526    }
527    if access_label == "full_scan" {
528        if explain_predicate_contains_non_strict_compare(predicate) {
529            return "fallback(non_strict_compare_coercion)".to_string();
530        }
531        if explain_predicate_contains_empty_prefix_starts_with(predicate) {
532            return "fallback(starts_with_empty_prefix)".to_string();
533        }
534        if explain_predicate_contains_is_null(predicate) {
535            return "fallback(is_null_full_scan)".to_string();
536        }
537        if explain_predicate_contains_text_scan_operator(predicate) {
538            return "fallback(text_operator_full_scan)".to_string();
539        }
540
541        return format!("fallback({access_label})");
542    }
543
544    format!("applied({access_label})")
545}
546
547// Detect predicates that force non-strict compare fallback diagnostics.
548fn explain_predicate_contains_non_strict_compare(predicate: &ExplainPredicate) -> bool {
549    match predicate {
550        ExplainPredicate::Compare { coercion, .. }
551        | ExplainPredicate::CompareFields { coercion, .. } => coercion.id != CoercionId::Strict,
552        ExplainPredicate::And(children) | ExplainPredicate::Or(children) => children
553            .iter()
554            .any(explain_predicate_contains_non_strict_compare),
555        ExplainPredicate::Not(inner) => explain_predicate_contains_non_strict_compare(inner),
556        ExplainPredicate::None
557        | ExplainPredicate::True
558        | ExplainPredicate::False
559        | ExplainPredicate::IsNull { .. }
560        | ExplainPredicate::IsNotNull { .. }
561        | ExplainPredicate::IsMissing { .. }
562        | ExplainPredicate::IsEmpty { .. }
563        | ExplainPredicate::IsNotEmpty { .. }
564        | ExplainPredicate::TextContains { .. }
565        | ExplainPredicate::TextContainsCi { .. } => false,
566    }
567}
568
569// Detect IS NULL predicates that force full-scan fallback diagnostics.
570fn explain_predicate_contains_is_null(predicate: &ExplainPredicate) -> bool {
571    match predicate {
572        ExplainPredicate::IsNull { .. } => true,
573        ExplainPredicate::And(children) | ExplainPredicate::Or(children) => {
574            children.iter().any(explain_predicate_contains_is_null)
575        }
576        ExplainPredicate::Not(inner) => explain_predicate_contains_is_null(inner),
577        ExplainPredicate::None
578        | ExplainPredicate::True
579        | ExplainPredicate::False
580        | ExplainPredicate::Compare { .. }
581        | ExplainPredicate::CompareFields { .. }
582        | ExplainPredicate::IsNotNull { .. }
583        | ExplainPredicate::IsMissing { .. }
584        | ExplainPredicate::IsEmpty { .. }
585        | ExplainPredicate::IsNotEmpty { .. }
586        | ExplainPredicate::TextContains { .. }
587        | ExplainPredicate::TextContainsCi { .. } => false,
588    }
589}
590
591// Detect empty starts_with predicates that force fallback diagnostics.
592fn explain_predicate_contains_empty_prefix_starts_with(predicate: &ExplainPredicate) -> bool {
593    match predicate {
594        ExplainPredicate::Compare {
595            op: CompareOp::StartsWith,
596            value: Value::Text(prefix),
597            ..
598        } => prefix.is_empty(),
599        ExplainPredicate::And(children) | ExplainPredicate::Or(children) => children
600            .iter()
601            .any(explain_predicate_contains_empty_prefix_starts_with),
602        ExplainPredicate::Not(inner) => explain_predicate_contains_empty_prefix_starts_with(inner),
603        ExplainPredicate::None
604        | ExplainPredicate::True
605        | ExplainPredicate::False
606        | ExplainPredicate::Compare { .. }
607        | ExplainPredicate::CompareFields { .. }
608        | ExplainPredicate::IsNull { .. }
609        | ExplainPredicate::IsNotNull { .. }
610        | ExplainPredicate::IsMissing { .. }
611        | ExplainPredicate::IsEmpty { .. }
612        | ExplainPredicate::IsNotEmpty { .. }
613        | ExplainPredicate::TextContains { .. }
614        | ExplainPredicate::TextContainsCi { .. } => false,
615    }
616}
617
618// Detect text scan predicates that force full-scan fallback diagnostics.
619fn explain_predicate_contains_text_scan_operator(predicate: &ExplainPredicate) -> bool {
620    match predicate {
621        ExplainPredicate::Compare {
622            op: CompareOp::EndsWith,
623            ..
624        }
625        | ExplainPredicate::TextContains { .. }
626        | ExplainPredicate::TextContainsCi { .. } => true,
627        ExplainPredicate::And(children) | ExplainPredicate::Or(children) => children
628            .iter()
629            .any(explain_predicate_contains_text_scan_operator),
630        ExplainPredicate::Not(inner) => explain_predicate_contains_text_scan_operator(inner),
631        ExplainPredicate::Compare { .. }
632        | ExplainPredicate::CompareFields { .. }
633        | ExplainPredicate::None
634        | ExplainPredicate::True
635        | ExplainPredicate::False
636        | ExplainPredicate::IsNull { .. }
637        | ExplainPredicate::IsNotNull { .. }
638        | ExplainPredicate::IsMissing { .. }
639        | ExplainPredicate::IsEmpty { .. }
640        | ExplainPredicate::IsNotEmpty { .. } => false,
641    }
642}