reddb_server/storage/query/planner/
rewriter.rs

1//! Query Rewriter
2//!
3//! Multi-pass AST transformation system inspired by Neo4j's query rewriting.
4//!
5//! # Rewrite Passes
6//!
7//! 1. **Normalize**: Standardize AST structure
8//! 2. **InjectCachedProperties**: Cache property lookups at compile time
9//! 3. **SimplifyFilters**: Combine and simplify filter expressions
10//! 4. **PushdownPredicates**: Move filters closer to data source
11//! 5. **ValidateFunctions**: Check function calls against schema
12
13use crate::storage::query::ast::{
14    CompareOp, FieldRef, Filter as AstFilter, JoinQuery, Projection, QueryExpr,
15};
16use crate::storage::query::sql_lowering::{
17    effective_graph_filter, effective_join_filter, effective_table_filter, effective_vector_filter,
18};
19use crate::storage::schema::Value;
20
21/// Context for rewrite operations
22#[derive(Debug, Clone, Default)]
23pub struct RewriteContext {
24    /// Property cache for compile-time lookups
25    pub property_cache: Vec<CachedProperty>,
26    /// Validation errors encountered
27    pub errors: Vec<String>,
28    /// Warnings generated
29    pub warnings: Vec<String>,
30    /// Statistics about rewrites
31    pub stats: RewriteStats,
32}
33
34/// A cached property lookup
35#[derive(Debug, Clone)]
36pub struct CachedProperty {
37    /// Source alias (table or node)
38    pub source: String,
39    /// Property name
40    pub property: String,
41    /// Cached value if known at compile time
42    pub cached_value: Option<String>,
43}
44
45/// Statistics about rewrite passes
46#[derive(Debug, Clone, Default)]
47pub struct RewriteStats {
48    /// Number of filters simplified
49    pub filters_simplified: u32,
50    /// Number of predicates pushed down
51    pub predicates_pushed: u32,
52    /// Number of properties cached
53    pub properties_cached: u32,
54    /// Number of expressions normalized
55    pub expressions_normalized: u32,
56}
57
58/// A rewrite rule that transforms query expressions
59pub trait RewriteRule: Send + Sync {
60    /// Rule name for debugging
61    fn name(&self) -> &str;
62
63    /// Apply the rule to a query expression
64    fn apply(&self, query: QueryExpr, ctx: &mut RewriteContext) -> QueryExpr;
65
66    /// Check if this rule is applicable to the query
67    fn is_applicable(&self, query: &QueryExpr) -> bool;
68}
69
70/// Query rewriter with pluggable rules
71pub struct QueryRewriter {
72    /// Ordered list of rewrite rules
73    rules: Vec<Box<dyn RewriteRule>>,
74    /// Maximum number of rewrite iterations
75    max_iterations: usize,
76}
77
78impl QueryRewriter {
79    /// Create a new rewriter with default rules
80    pub fn new() -> Self {
81        let rules: Vec<Box<dyn RewriteRule>> = vec![
82            Box::new(NormalizeRule),
83            Box::new(SimplifyFiltersRule),
84            Box::new(PushdownPredicatesRule),
85            Box::new(EliminateDeadCodeRule),
86            Box::new(FoldConstantsRule),
87        ];
88
89        Self {
90            rules,
91            max_iterations: 10,
92        }
93    }
94
95    /// Add a custom rewrite rule
96    pub fn add_rule(&mut self, rule: Box<dyn RewriteRule>) {
97        self.rules.push(rule);
98    }
99
100    /// Rewrite a query expression
101    pub fn rewrite(&self, query: QueryExpr) -> QueryExpr {
102        let mut ctx = RewriteContext::default();
103        self.rewrite_with_context(query, &mut ctx)
104    }
105
106    /// Rewrite with access to context
107    pub fn rewrite_with_context(
108        &self,
109        mut query: QueryExpr,
110        ctx: &mut RewriteContext,
111    ) -> QueryExpr {
112        // Apply rules iteratively until fixed point
113        for _iteration in 0..self.max_iterations {
114            let original = format!("{:?}", query);
115
116            for rule in &self.rules {
117                if rule.is_applicable(&query) {
118                    query = rule.apply(query, ctx);
119                }
120            }
121
122            // Check for fixed point
123            if format!("{:?}", query) == original {
124                break;
125            }
126        }
127
128        query
129    }
130}
131
132impl Default for QueryRewriter {
133    fn default() -> Self {
134        Self::new()
135    }
136}
137
138// =============================================================================
139// Built-in Rewrite Rules
140// =============================================================================
141
142/// Normalize AST structure
143struct NormalizeRule;
144
145impl RewriteRule for NormalizeRule {
146    fn name(&self) -> &str {
147        "Normalize"
148    }
149
150    fn apply(&self, query: QueryExpr, ctx: &mut RewriteContext) -> QueryExpr {
151        match query {
152            QueryExpr::Table(mut tq) => {
153                // Normalize column order
154                tq.columns.sort_by(|a, b| {
155                    let a_name = projection_name(a);
156                    let b_name = projection_name(b);
157                    a_name.cmp(&b_name)
158                });
159                ctx.stats.expressions_normalized += 1;
160                QueryExpr::Table(tq)
161            }
162            QueryExpr::Graph(gq) => {
163                // Graph queries don't need normalization currently
164                QueryExpr::Graph(gq)
165            }
166            QueryExpr::Join(jq) => {
167                // Recursively normalize children
168                let left = self.apply(*jq.left, ctx);
169                let right = self.apply(*jq.right, ctx);
170                QueryExpr::Join(JoinQuery {
171                    left: Box::new(left),
172                    right: Box::new(right),
173                    ..jq
174                })
175            }
176            QueryExpr::Path(pq) => QueryExpr::Path(pq),
177            QueryExpr::Vector(vq) => {
178                // Vector queries don't need normalization currently
179                QueryExpr::Vector(vq)
180            }
181            QueryExpr::Hybrid(mut hq) => {
182                // Normalize the structured part
183                hq.structured = Box::new(self.apply(*hq.structured, ctx));
184                QueryExpr::Hybrid(hq)
185            }
186            // DML/DDL/Command statements pass through without normalization
187            other @ (QueryExpr::Insert(_)
188            | QueryExpr::Update(_)
189            | QueryExpr::Delete(_)
190            | QueryExpr::CreateTable(_)
191            | QueryExpr::DropTable(_)
192            | QueryExpr::DropGraph(_)
193            | QueryExpr::DropVector(_)
194            | QueryExpr::DropDocument(_)
195            | QueryExpr::DropKv(_)
196            | QueryExpr::DropCollection(_)
197            | QueryExpr::Truncate(_)
198            | QueryExpr::AlterTable(_)
199            | QueryExpr::GraphCommand(_)
200            | QueryExpr::SearchCommand(_)
201            | QueryExpr::CreateIndex(_)
202            | QueryExpr::DropIndex(_)
203            | QueryExpr::ProbabilisticCommand(_)
204            | QueryExpr::Ask(_)
205            | QueryExpr::SetConfig { .. }
206            | QueryExpr::ShowConfig { .. }
207            | QueryExpr::SetSecret { .. }
208            | QueryExpr::DeleteSecret { .. }
209            | QueryExpr::ShowSecrets { .. }
210            | QueryExpr::SetTenant(_)
211            | QueryExpr::ShowTenant
212            | QueryExpr::CreateTimeSeries(_)
213            | QueryExpr::DropTimeSeries(_)
214            | QueryExpr::CreateQueue(_)
215            | QueryExpr::AlterQueue(_)
216            | QueryExpr::DropQueue(_)
217            | QueryExpr::QueueSelect(_)
218            | QueryExpr::QueueCommand(_)
219            | QueryExpr::KvCommand(_)
220            | QueryExpr::ConfigCommand(_)
221            | QueryExpr::CreateTree(_)
222            | QueryExpr::DropTree(_)
223            | QueryExpr::TreeCommand(_)
224            | QueryExpr::ExplainAlter(_)
225            | QueryExpr::TransactionControl(_)
226            | QueryExpr::MaintenanceCommand(_)
227            | QueryExpr::CreateSchema(_)
228            | QueryExpr::DropSchema(_)
229            | QueryExpr::CreateSequence(_)
230            | QueryExpr::DropSequence(_)
231            | QueryExpr::CopyFrom(_)
232            | QueryExpr::CreateView(_)
233            | QueryExpr::DropView(_)
234            | QueryExpr::RefreshMaterializedView(_)
235            | QueryExpr::CreatePolicy(_)
236            | QueryExpr::DropPolicy(_)
237            | QueryExpr::CreateServer(_)
238            | QueryExpr::DropServer(_)
239            | QueryExpr::CreateForeignTable(_)
240            | QueryExpr::DropForeignTable(_)
241            | QueryExpr::Grant(_)
242            | QueryExpr::Revoke(_)
243            | QueryExpr::AlterUser(_)
244            | QueryExpr::CreateIamPolicy { .. }
245            | QueryExpr::DropIamPolicy { .. }
246            | QueryExpr::AttachPolicy { .. }
247            | QueryExpr::DetachPolicy { .. }
248            | QueryExpr::ShowPolicies { .. }
249            | QueryExpr::ShowEffectivePermissions { .. }
250            | QueryExpr::SimulatePolicy { .. }
251            | QueryExpr::CreateMigration(_)
252            | QueryExpr::ApplyMigration(_)
253            | QueryExpr::RollbackMigration(_)
254            | QueryExpr::ExplainMigration(_)
255            | QueryExpr::EventsBackfill(_)
256            | QueryExpr::EventsBackfillStatus { .. }) => other,
257        }
258    }
259
260    fn is_applicable(&self, _query: &QueryExpr) -> bool {
261        true
262    }
263}
264
265/// Simplify filter expressions
266struct SimplifyFiltersRule;
267
268impl RewriteRule for SimplifyFiltersRule {
269    fn name(&self) -> &str {
270        "SimplifyFilters"
271    }
272
273    fn apply(&self, query: QueryExpr, ctx: &mut RewriteContext) -> QueryExpr {
274        match query {
275            QueryExpr::Table(mut tq) => {
276                if let Some(filter) = effective_table_filter(&tq) {
277                    tq.filter = Some(simplify_filter(filter, ctx));
278                }
279                QueryExpr::Table(tq)
280            }
281            QueryExpr::Graph(mut gq) => {
282                if let Some(filter) = effective_graph_filter(&gq) {
283                    gq.filter = Some(simplify_filter(filter, ctx));
284                }
285                QueryExpr::Graph(gq)
286            }
287            QueryExpr::Join(mut jq) => {
288                let join_filter = effective_join_filter(&jq);
289                let left = self.apply(*jq.left, ctx);
290                let right = self.apply(*jq.right, ctx);
291                if let Some(filter) = join_filter {
292                    jq.filter = Some(simplify_filter(filter, ctx));
293                }
294                jq.left = Box::new(left);
295                jq.right = Box::new(right);
296                QueryExpr::Join(jq)
297            }
298            QueryExpr::Path(pq) => QueryExpr::Path(pq),
299            QueryExpr::Vector(vq) => {
300                // Vector queries have MetadataFilter, not AstFilter
301                // Pass through for now
302                QueryExpr::Vector(vq)
303            }
304            QueryExpr::Hybrid(mut hq) => {
305                // Simplify filters in the structured part
306                hq.structured = Box::new(self.apply(*hq.structured, ctx));
307                QueryExpr::Hybrid(hq)
308            }
309            // DML/DDL/Command statements pass through without filter simplification
310            other @ (QueryExpr::Insert(_)
311            | QueryExpr::Update(_)
312            | QueryExpr::Delete(_)
313            | QueryExpr::CreateTable(_)
314            | QueryExpr::DropTable(_)
315            | QueryExpr::DropGraph(_)
316            | QueryExpr::DropVector(_)
317            | QueryExpr::DropDocument(_)
318            | QueryExpr::DropKv(_)
319            | QueryExpr::DropCollection(_)
320            | QueryExpr::Truncate(_)
321            | QueryExpr::AlterTable(_)
322            | QueryExpr::GraphCommand(_)
323            | QueryExpr::SearchCommand(_)
324            | QueryExpr::CreateIndex(_)
325            | QueryExpr::DropIndex(_)
326            | QueryExpr::ProbabilisticCommand(_)
327            | QueryExpr::Ask(_)
328            | QueryExpr::SetConfig { .. }
329            | QueryExpr::ShowConfig { .. }
330            | QueryExpr::SetSecret { .. }
331            | QueryExpr::DeleteSecret { .. }
332            | QueryExpr::ShowSecrets { .. }
333            | QueryExpr::SetTenant(_)
334            | QueryExpr::ShowTenant
335            | QueryExpr::CreateTimeSeries(_)
336            | QueryExpr::DropTimeSeries(_)
337            | QueryExpr::CreateQueue(_)
338            | QueryExpr::AlterQueue(_)
339            | QueryExpr::DropQueue(_)
340            | QueryExpr::QueueSelect(_)
341            | QueryExpr::QueueCommand(_)
342            | QueryExpr::KvCommand(_)
343            | QueryExpr::ConfigCommand(_)
344            | QueryExpr::CreateTree(_)
345            | QueryExpr::DropTree(_)
346            | QueryExpr::TreeCommand(_)
347            | QueryExpr::ExplainAlter(_)
348            | QueryExpr::TransactionControl(_)
349            | QueryExpr::MaintenanceCommand(_)
350            | QueryExpr::CreateSchema(_)
351            | QueryExpr::DropSchema(_)
352            | QueryExpr::CreateSequence(_)
353            | QueryExpr::DropSequence(_)
354            | QueryExpr::CopyFrom(_)
355            | QueryExpr::CreateView(_)
356            | QueryExpr::DropView(_)
357            | QueryExpr::RefreshMaterializedView(_)
358            | QueryExpr::CreatePolicy(_)
359            | QueryExpr::DropPolicy(_)
360            | QueryExpr::CreateServer(_)
361            | QueryExpr::DropServer(_)
362            | QueryExpr::CreateForeignTable(_)
363            | QueryExpr::DropForeignTable(_)
364            | QueryExpr::Grant(_)
365            | QueryExpr::Revoke(_)
366            | QueryExpr::AlterUser(_)
367            | QueryExpr::CreateIamPolicy { .. }
368            | QueryExpr::DropIamPolicy { .. }
369            | QueryExpr::AttachPolicy { .. }
370            | QueryExpr::DetachPolicy { .. }
371            | QueryExpr::ShowPolicies { .. }
372            | QueryExpr::ShowEffectivePermissions { .. }
373            | QueryExpr::SimulatePolicy { .. }
374            | QueryExpr::CreateMigration(_)
375            | QueryExpr::ApplyMigration(_)
376            | QueryExpr::RollbackMigration(_)
377            | QueryExpr::ExplainMigration(_)
378            | QueryExpr::EventsBackfill(_)
379            | QueryExpr::EventsBackfillStatus { .. }) => other,
380        }
381    }
382
383    fn is_applicable(&self, query: &QueryExpr) -> bool {
384        match query {
385            QueryExpr::Table(tq) => effective_table_filter(tq).is_some(),
386            QueryExpr::Graph(gq) => effective_graph_filter(gq).is_some(),
387            QueryExpr::Join(_) => true,
388            QueryExpr::Path(_) => false,
389            QueryExpr::Vector(vq) => effective_vector_filter(vq).is_some(),
390            QueryExpr::Hybrid(_) => true, // May have filters in structured part
391            // DML/DDL/Command statements are not applicable for filter simplification
392            QueryExpr::Insert(_)
393            | QueryExpr::Update(_)
394            | QueryExpr::Delete(_)
395            | QueryExpr::CreateTable(_)
396            | QueryExpr::DropTable(_)
397            | QueryExpr::DropGraph(_)
398            | QueryExpr::DropVector(_)
399            | QueryExpr::DropDocument(_)
400            | QueryExpr::DropKv(_)
401            | QueryExpr::DropCollection(_)
402            | QueryExpr::Truncate(_)
403            | QueryExpr::AlterTable(_)
404            | QueryExpr::GraphCommand(_)
405            | QueryExpr::SearchCommand(_)
406            | QueryExpr::CreateIndex(_)
407            | QueryExpr::DropIndex(_)
408            | QueryExpr::ProbabilisticCommand(_)
409            | QueryExpr::Ask(_)
410            | QueryExpr::SetConfig { .. }
411            | QueryExpr::ShowConfig { .. }
412            | QueryExpr::SetSecret { .. }
413            | QueryExpr::DeleteSecret { .. }
414            | QueryExpr::ShowSecrets { .. }
415            | QueryExpr::SetTenant(_)
416            | QueryExpr::ShowTenant
417            | QueryExpr::CreateTimeSeries(_)
418            | QueryExpr::DropTimeSeries(_)
419            | QueryExpr::CreateQueue(_)
420            | QueryExpr::AlterQueue(_)
421            | QueryExpr::DropQueue(_)
422            | QueryExpr::QueueSelect(_)
423            | QueryExpr::QueueCommand(_)
424            | QueryExpr::KvCommand(_)
425            | QueryExpr::ConfigCommand(_)
426            | QueryExpr::CreateTree(_)
427            | QueryExpr::DropTree(_)
428            | QueryExpr::TreeCommand(_)
429            | QueryExpr::ExplainAlter(_)
430            | QueryExpr::TransactionControl(_)
431            | QueryExpr::MaintenanceCommand(_)
432            | QueryExpr::CreateSchema(_)
433            | QueryExpr::DropSchema(_)
434            | QueryExpr::CreateSequence(_)
435            | QueryExpr::DropSequence(_)
436            | QueryExpr::CopyFrom(_)
437            | QueryExpr::CreateView(_)
438            | QueryExpr::DropView(_)
439            | QueryExpr::RefreshMaterializedView(_)
440            | QueryExpr::CreatePolicy(_)
441            | QueryExpr::DropPolicy(_)
442            | QueryExpr::CreateServer(_)
443            | QueryExpr::DropServer(_)
444            | QueryExpr::CreateForeignTable(_)
445            | QueryExpr::DropForeignTable(_)
446            | QueryExpr::Grant(_)
447            | QueryExpr::Revoke(_)
448            | QueryExpr::AlterUser(_)
449            | QueryExpr::CreateIamPolicy { .. }
450            | QueryExpr::DropIamPolicy { .. }
451            | QueryExpr::AttachPolicy { .. }
452            | QueryExpr::DetachPolicy { .. }
453            | QueryExpr::ShowPolicies { .. }
454            | QueryExpr::ShowEffectivePermissions { .. }
455            | QueryExpr::SimulatePolicy { .. }
456            | QueryExpr::CreateMigration(_)
457            | QueryExpr::ApplyMigration(_)
458            | QueryExpr::RollbackMigration(_)
459            | QueryExpr::ExplainMigration(_)
460            | QueryExpr::EventsBackfill(_)
461            | QueryExpr::EventsBackfillStatus { .. } => false,
462        }
463    }
464}
465
466/// Push predicates down to data sources
467struct PushdownPredicatesRule;
468
469impl RewriteRule for PushdownPredicatesRule {
470    fn name(&self) -> &str {
471        "PushdownPredicates"
472    }
473
474    fn apply(&self, query: QueryExpr, ctx: &mut RewriteContext) -> QueryExpr {
475        match query {
476            QueryExpr::Join(mut jq) => {
477                // Try to push join predicates down to children
478                // This is a simplified version - real implementation would analyze
479                // which predicates can be pushed to which child
480
481                // For now, just recursively apply to children
482                jq.left = Box::new(self.apply(*jq.left, ctx));
483                jq.right = Box::new(self.apply(*jq.right, ctx));
484                ctx.stats.predicates_pushed += 1;
485                QueryExpr::Join(jq)
486            }
487            other => other,
488        }
489    }
490
491    fn is_applicable(&self, query: &QueryExpr) -> bool {
492        matches!(query, QueryExpr::Join(_))
493    }
494}
495
496/// Eliminate dead code branches
497struct EliminateDeadCodeRule;
498
499impl RewriteRule for EliminateDeadCodeRule {
500    fn name(&self) -> &str {
501        "EliminateDeadCode"
502    }
503
504    fn apply(&self, query: QueryExpr, _ctx: &mut RewriteContext) -> QueryExpr {
505        match query {
506            QueryExpr::Table(mut tq) => {
507                // Remove always-true filters
508                if let Some(filter) = effective_table_filter(&tq).as_ref() {
509                    if is_always_true(filter) {
510                        tq.filter = None;
511                    }
512                }
513                QueryExpr::Table(tq)
514            }
515            other => other,
516        }
517    }
518
519    fn is_applicable(&self, query: &QueryExpr) -> bool {
520        matches!(query, QueryExpr::Table(_))
521    }
522}
523
524/// Fold constant expressions
525struct FoldConstantsRule;
526
527impl RewriteRule for FoldConstantsRule {
528    fn name(&self) -> &str {
529        "FoldConstants"
530    }
531
532    fn apply(&self, query: QueryExpr, _ctx: &mut RewriteContext) -> QueryExpr {
533        // Constant folding is complex - for now just pass through
534        // A real implementation would evaluate constant expressions at compile time
535        query
536    }
537
538    fn is_applicable(&self, _query: &QueryExpr) -> bool {
539        true
540    }
541}
542
543// =============================================================================
544// Helper Functions
545// =============================================================================
546
547fn projection_name(proj: &Projection) -> String {
548    match proj {
549        Projection::All => "*".to_string(),
550        Projection::Column(name) => name.clone(),
551        Projection::Alias(_, alias) => alias.clone(),
552        Projection::Function(name, _) => name.clone(),
553        Projection::Expression(expr, _) => format!("{:?}", expr),
554        Projection::Field(field, alias) => alias.clone().unwrap_or_else(|| format!("{:?}", field)),
555    }
556}
557
558fn simplify_filter(filter: AstFilter, ctx: &mut RewriteContext) -> AstFilter {
559    match filter {
560        AstFilter::And(left, right) => {
561            let left = simplify_filter(*left, ctx);
562            let right = simplify_filter(*right, ctx);
563
564            // AND with TRUE -> other side
565            if is_always_true(&left) {
566                ctx.stats.filters_simplified += 1;
567                return right;
568            }
569            if is_always_true(&right) {
570                ctx.stats.filters_simplified += 1;
571                return left;
572            }
573
574            // AND with FALSE -> FALSE
575            if is_always_false(&left) || is_always_false(&right) {
576                ctx.stats.filters_simplified += 1;
577                return AstFilter::Compare {
578                    field: FieldRef::TableColumn {
579                        table: String::new(),
580                        column: "1".to_string(),
581                    },
582                    op: CompareOp::Eq,
583                    value: Value::Integer(0),
584                };
585            }
586
587            AstFilter::And(Box::new(left), Box::new(right))
588        }
589        AstFilter::Or(left, right) => {
590            let left = simplify_filter(*left, ctx);
591            let right = simplify_filter(*right, ctx);
592
593            // OR with FALSE -> other side
594            if is_always_false(&left) {
595                ctx.stats.filters_simplified += 1;
596                return right;
597            }
598            if is_always_false(&right) {
599                ctx.stats.filters_simplified += 1;
600                return left;
601            }
602
603            // OR with TRUE -> TRUE
604            if is_always_true(&left) || is_always_true(&right) {
605                ctx.stats.filters_simplified += 1;
606                return AstFilter::Compare {
607                    field: FieldRef::TableColumn {
608                        table: String::new(),
609                        column: "1".to_string(),
610                    },
611                    op: CompareOp::Eq,
612                    value: Value::Integer(1),
613                };
614            }
615
616            AstFilter::Or(Box::new(left), Box::new(right))
617        }
618        AstFilter::Not(inner) => {
619            let inner = simplify_filter(*inner, ctx);
620
621            // NOT NOT x -> x
622            if let AstFilter::Not(double_inner) = inner {
623                ctx.stats.filters_simplified += 1;
624                return *double_inner;
625            }
626
627            AstFilter::Not(Box::new(inner))
628        }
629        other => other,
630    }
631}
632
633fn is_always_true(filter: &AstFilter) -> bool {
634    match filter {
635        AstFilter::Compare { field, op, value } => {
636            // 1 = 1 is always true
637            matches!(field, FieldRef::TableColumn { column, .. } if column == "1")
638                && matches!(op, CompareOp::Eq)
639                && matches!(value, Value::Integer(1))
640        }
641        _ => false,
642    }
643}
644
645fn is_always_false(filter: &AstFilter) -> bool {
646    match filter {
647        AstFilter::Compare { field, op, value } => {
648            // 1 = 0 is always false
649            matches!(field, FieldRef::TableColumn { column, .. } if column == "1")
650                && matches!(op, CompareOp::Eq)
651                && matches!(value, Value::Integer(0))
652        }
653        _ => false,
654    }
655}
656
657#[cfg(test)]
658mod tests {
659    use super::*;
660
661    fn make_field(name: &str) -> FieldRef {
662        FieldRef::TableColumn {
663            table: String::new(),
664            column: name.to_string(),
665        }
666    }
667
668    #[test]
669    fn test_simplify_and_with_true() {
670        let mut ctx = RewriteContext::default();
671
672        let filter = AstFilter::And(
673            Box::new(AstFilter::Compare {
674                field: make_field("1"),
675                op: CompareOp::Eq,
676                value: Value::Integer(1),
677            }),
678            Box::new(AstFilter::Compare {
679                field: make_field("x"),
680                op: CompareOp::Eq,
681                value: Value::Integer(5),
682            }),
683        );
684
685        let simplified = simplify_filter(filter, &mut ctx);
686
687        match simplified {
688            AstFilter::Compare { field, .. } => {
689                assert!(matches!(field, FieldRef::TableColumn { column, .. } if column == "x"));
690            }
691            _ => panic!("Expected Compare filter"),
692        }
693    }
694
695    #[test]
696    fn test_simplify_double_not() {
697        let mut ctx = RewriteContext::default();
698
699        let filter = AstFilter::Not(Box::new(AstFilter::Not(Box::new(AstFilter::Compare {
700            field: make_field("x"),
701            op: CompareOp::Eq,
702            value: Value::Integer(5),
703        }))));
704
705        let simplified = simplify_filter(filter, &mut ctx);
706
707        match simplified {
708            AstFilter::Compare { field, .. } => {
709                assert!(matches!(field, FieldRef::TableColumn { column, .. } if column == "x"));
710            }
711            _ => panic!("Expected Compare filter"),
712        }
713    }
714}
reddb_server/storage/query/planner/rewriter.rs

reddb_server/storage/query/planner/
rewriter.rs
