From ffe9ba7db32a07cc492046dd8999b6ac55e22265 Mon Sep 17 00:00:00 2001
From: Arseniy Volynets <vol0ncar@yandex.ru>
Date: Wed, 15 May 2024 00:14:58 +0000
Subject: [PATCH] fix: double motion under left join in case of cte
---
sbroad-core/src/frontend/sql/ir/tests/cte.rs | 32 +++++++++++++++++++
.../redistribution/left_join.rs | 29 +++++++++++++++--
2 files changed, 58 insertions(+), 3 deletions(-)
diff --git a/sbroad-core/src/frontend/sql/ir/tests/cte.rs b/sbroad-core/src/frontend/sql/ir/tests/cte.rs
index 26c0b7a02a..ca97c9bb27 100644
--- a/sbroad-core/src/frontend/sql/ir/tests/cte.rs
+++ b/sbroad-core/src/frontend/sql/ir/tests/cte.rs
@@ -417,3 +417,35 @@ fn cte_column_mismatch() {
))
);
}
+
+#[test]
+fn cte_with_left_join() {
+ let sql = r#"
+ with cte as (select "e" as e from "t2")
+ select e from cte left join "t2"
+ on true
+ "#;
+
+ let plan = sql_to_optimized_ir(sql, vec![]);
+
+ let expected_explain = String::from(
+ r#"projection ("E"::unsigned -> "E")
+ motion [policy: full]
+ scan
+ projection ("CTE"."E"::unsigned -> "E", "t2"."e"::unsigned -> "e", "t2"."f"::unsigned -> "f", "t2"."g"::unsigned -> "g", "t2"."h"::unsigned -> "h")
+ join on true::boolean
+ scan cte "CTE"($0)
+ scan "t2"
+ projection ("t2"."e"::unsigned -> "e", "t2"."f"::unsigned -> "f", "t2"."g"::unsigned -> "g", "t2"."h"::unsigned -> "h")
+ scan "t2"
+subquery $0:
+motion [policy: full]
+ projection ("t2"."e"::unsigned -> "E")
+ scan "t2"
+execution options:
+sql_vdbe_max_steps = 45000
+vtable_max_rows = 5000
+"#,
+ );
+ assert_eq!(expected_explain, plan.as_explain().unwrap());
+}
diff --git a/sbroad-core/src/ir/transformation/redistribution/left_join.rs b/sbroad-core/src/ir/transformation/redistribution/left_join.rs
index 0e6691ba14..064d3bb7ff 100644
--- a/sbroad-core/src/ir/transformation/redistribution/left_join.rs
+++ b/sbroad-core/src/ir/transformation/redistribution/left_join.rs
@@ -51,9 +51,32 @@ impl Plan {
self.change_child(parent_id, join_id, sq_id)?;
let outer_id = self.get_relational_child(join_id, 0)?;
- let outer_child_motion_id =
- self.add_motion(outer_id, &MotionPolicy::Full, Program::default())?;
- self.change_child(join_id, outer_id, outer_child_motion_id)?;
+
+ // In case there are no motions under outer child,
+ // we need to add one, because we need to materialize
+ // the subtree from which missing rows will be added.
+ let outer_child_motion_id = {
+ let child = self.get_relation_node(outer_id)?;
+ let mut motion_child_id = None;
+
+ // Check if there is already motion under outer child
+ if child.is_subquery_or_cte() {
+ let sq_child = self.get_relational_child(outer_id, 0)?;
+ if self.get_relation_node(sq_child)?.is_motion() {
+ motion_child_id = Some(sq_child);
+ }
+ } else if child.is_motion() {
+ motion_child_id = Some(outer_id);
+ }
+
+ if motion_child_id.is_none() {
+ let motion_id =
+ self.add_motion(outer_id, &MotionPolicy::Full, Program::default())?;
+ self.change_child(join_id, outer_id, motion_id)?;
+ motion_child_id = Some(motion_id);
+ }
+ motion_child_id.unwrap()
+ };
// Add motion which will do the reduce stage of joining:
// adding missing rows.
--
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