test: add crdb/limit.slt (#216)

* test: add `crdb/limit.slt`

* ci: add args `--all` on cargo test

.github/workflows/ci.yml

@@ -44,6 +44,7 @@ jobs:
         uses: actions-rs/cargo@v1
         with:
           command: test
+          args: --all
   # 2
   fmt:
     name: Rust fmt

src/db.rs

@@ -201,22 +201,21 @@ impl<S: Storage> Database<S> {
                 ],
             )
             .batch(
-                "Combine Operators".to_string(),
+                "Limit Pushdown".to_string(),
                 HepBatchStrategy::fix_point_topdown(10),
                 vec![
-                    NormalizationRuleImpl::CollapseProject,
-                    NormalizationRuleImpl::CollapseGroupByAgg,
-                    NormalizationRuleImpl::CombineFilter,
+                    NormalizationRuleImpl::LimitProjectTranspose,
+                    NormalizationRuleImpl::PushLimitThroughJoin,
+                    NormalizationRuleImpl::PushLimitIntoTableScan,
                 ],
             )
             .batch(
-                "Limit Pushdown".to_string(),
+                "Combine Operators".to_string(),
                 HepBatchStrategy::fix_point_topdown(10),
                 vec![
-                    NormalizationRuleImpl::LimitProjectTranspose,
-                    NormalizationRuleImpl::PushLimitThroughJoin,
-                    NormalizationRuleImpl::PushLimitIntoTableScan,
-                    NormalizationRuleImpl::EliminateLimits,
+                    NormalizationRuleImpl::CollapseProject,
+                    NormalizationRuleImpl::CollapseGroupByAgg,
+                    NormalizationRuleImpl::CombineFilter,
                 ],
             )
             .batch(
@@ -364,7 +363,9 @@ mod test {
     fn test_udtf() -> Result<(), DatabaseError> {
         let temp_dir = TempDir::new().expect("unable to create temporary working directory");
         let fnck_sql = DataBaseBuilder::path(temp_dir.path()).build()?;
-        let (schema, tuples) = fnck_sql.run("select number from table(numbers(10))")?;
+        let (schema, tuples) = fnck_sql.run(
+            "SELECT * FROM (select * from table(numbers(10)) a ORDER BY number LIMIT 5) OFFSET 3",
+        )?;
         println!("{}", create_table(&schema, &tuples));
 
         Ok(())

src/execution/dql/limit.rs

@@ -42,7 +42,7 @@ impl<'a, T: Transaction + 'a> ReadExecutor<'a, T> for Limit {
                 }
 
                 let offset_val = offset.unwrap_or(0);
-                let offset_limit = offset_val + limit.unwrap_or(1) - 1;
+                let offset_limit = offset_val.saturating_add(limit.unwrap_or(usize::MAX)) - 1;
 
                 let mut i = 0;
                 let mut coroutine = build_read(input, cache, transaction);

src/optimizer/rule/normalization/mod.rs

@@ -11,7 +11,7 @@ use crate::optimizer::rule::normalization::compilation_in_advance::{
     EvaluatorBind, ExpressionRemapper,
 };
 use crate::optimizer::rule::normalization::pushdown_limit::{
-    EliminateLimits, LimitProjectTranspose, PushLimitIntoScan, PushLimitThroughJoin,
+    LimitProjectTranspose, PushLimitIntoScan, PushLimitThroughJoin,
 };
 use crate::optimizer::rule::normalization::pushdown_predicates::PushPredicateIntoScan;
 use crate::optimizer::rule::normalization::pushdown_predicates::PushPredicateThroughJoin;
@@ -34,7 +34,6 @@ pub enum NormalizationRuleImpl {
     CombineFilter,
     // PushDown limit
     LimitProjectTranspose,
-    EliminateLimits,
     PushLimitThroughJoin,
     PushLimitIntoTableScan,
     // PushDown predicates
@@ -57,7 +56,6 @@ impl MatchPattern for NormalizationRuleImpl {
             NormalizationRuleImpl::CollapseGroupByAgg => CollapseGroupByAgg.pattern(),
             NormalizationRuleImpl::CombineFilter => CombineFilter.pattern(),
             NormalizationRuleImpl::LimitProjectTranspose => LimitProjectTranspose.pattern(),
-            NormalizationRuleImpl::EliminateLimits => EliminateLimits.pattern(),
             NormalizationRuleImpl::PushLimitThroughJoin => PushLimitThroughJoin.pattern(),
             NormalizationRuleImpl::PushLimitIntoTableScan => PushLimitIntoScan.pattern(),
             NormalizationRuleImpl::PushPredicateThroughJoin => PushPredicateThroughJoin.pattern(),
@@ -80,7 +78,6 @@ impl NormalizationRule for NormalizationRuleImpl {
             NormalizationRuleImpl::LimitProjectTranspose => {
                 LimitProjectTranspose.apply(node_id, graph)
             }
-            NormalizationRuleImpl::EliminateLimits => EliminateLimits.apply(node_id, graph),
             NormalizationRuleImpl::PushLimitThroughJoin => {
                 PushLimitThroughJoin.apply(node_id, graph)
             }

src/optimizer/rule/normalization/pushdown_limit.rs

@@ -4,11 +4,10 @@ use crate::optimizer::core::pattern::PatternChildrenPredicate;
 use crate::optimizer::core::rule::{MatchPattern, NormalizationRule};
 use crate::optimizer::heuristic::graph::{HepGraph, HepNodeId};
 use crate::planner::operator::join::JoinType;
-use crate::planner::operator::limit::LimitOperator;
 use crate::planner::operator::Operator;
 use itertools::Itertools;
 use lazy_static::lazy_static;
-use std::cmp;
+
 lazy_static! {
     static ref LIMIT_PROJECT_TRANSPOSE_RULE: Pattern = {
         Pattern {
@@ -66,51 +65,6 @@ impl NormalizationRule for LimitProjectTranspose {
     }
 }
 
-/// Combines two adjacent Limit operators into one, merging the expressions into one single
-/// expression.
-pub struct EliminateLimits;
-
-impl MatchPattern for EliminateLimits {
-    fn pattern(&self) -> &Pattern {
-        &ELIMINATE_LIMITS_RULE
-    }
-}
-
-impl NormalizationRule for EliminateLimits {
-    fn apply(&self, node_id: HepNodeId, graph: &mut HepGraph) -> Result<(), DatabaseError> {
-        if let Operator::Limit(op) = graph.operator(node_id) {
-            if let Some(child_id) = graph.eldest_child_at(node_id) {
-                if let Operator::Limit(child_op) = graph.operator(child_id) {
-                    let offset = Self::binary_options(op.offset, child_op.offset, |a, b| a + b);
-                    let limit = Self::binary_options(op.limit, child_op.limit, cmp::min);
-
-                    let new_limit_op = LimitOperator { offset, limit };
-
-                    graph.remove_node(child_id, false);
-                    graph.replace_node(node_id, Operator::Limit(new_limit_op));
-                }
-            }
-        }
-
-        Ok(())
-    }
-}
-
-impl EliminateLimits {
-    fn binary_options<F: Fn(usize, usize) -> usize>(
-        a: Option<usize>,
-        b: Option<usize>,
-        _fn: F,
-    ) -> Option<usize> {
-        match (a, b) {
-            (Some(a), Some(b)) => Some(_fn(a, b)),
-            (Some(a), None) => Some(a),
-            (None, Some(b)) => Some(b),
-            (None, None) => None,
-        }
-    }
-}
-
 /// Add extra limits below JOIN:
 /// 1. For LEFT OUTER and RIGHT OUTER JOIN, we push limits to the left and right sides,
 /// respectively.
@@ -190,7 +144,6 @@ mod tests {
     use crate::optimizer::heuristic::batch::HepBatchStrategy;
     use crate::optimizer::heuristic::optimizer::HepOptimizer;
     use crate::optimizer::rule::normalization::NormalizationRuleImpl;
-    use crate::planner::operator::limit::LimitOperator;
     use crate::planner::operator::Operator;
     use crate::storage::rocksdb::RocksTransaction;
 
@@ -219,39 +172,6 @@ mod tests {
         Ok(())
     }
 
-    #[test]
-    fn test_eliminate_limits() -> Result<(), DatabaseError> {
-        let plan = select_sql_run("select c1, c2 from t1 limit 1 offset 1")?;
-
-        let mut optimizer = HepOptimizer::new(plan.clone()).batch(
-            "test_eliminate_limits".to_string(),
-            HepBatchStrategy::once_topdown(),
-            vec![NormalizationRuleImpl::EliminateLimits],
-        );
-
-        let new_limit_op = LimitOperator {
-            offset: Some(2),
-            limit: Some(1),
-        };
-
-        optimizer.graph.add_root(Operator::Limit(new_limit_op));
-
-        let best_plan = optimizer.find_best::<RocksTransaction>(None)?;
-
-        if let Operator::Limit(op) = &best_plan.operator {
-            assert_eq!(op.limit, Some(1));
-            assert_eq!(op.offset, Some(3));
-        } else {
-            unreachable!("Should be a project operator")
-        }
-
-        if let Operator::Limit(_) = &best_plan.childrens[0].operator {
-            unreachable!("Should not be a limit operator")
-        }
-
-        Ok(())
-    }
-
     #[test]
     fn test_push_limit_through_join() -> Result<(), DatabaseError> {
         let plan = select_sql_run("select * from t1 left join t2 on c1 = c3 limit 1")?;