From c4ab2a718b6b2a5d1927a81793daab5cb9e3ab52 Mon Sep 17 00:00:00 2001
From: Denis Smirnov <sd@picodata.io>
Date: Wed, 20 Apr 2022 23:13:12 +0700
Subject: [PATCH] perf: reduce row tree traversion when build sql from ir
---
.../engine/cartridge/backend/sql/tree.rs | 8 ++-
src/ir/transformation/redistribution.rs | 55 ++++++++++++++-----
2 files changed, 46 insertions(+), 17 deletions(-)
diff --git a/src/executor/engine/cartridge/backend/sql/tree.rs b/src/executor/engine/cartridge/backend/sql/tree.rs
index 020060091f..4437219a76 100644
--- a/src/executor/engine/cartridge/backend/sql/tree.rs
+++ b/src/executor/engine/cartridge/backend/sql/tree.rs
@@ -522,7 +522,11 @@ impl<'p> SyntaxPlan<'p> {
Ok(self.nodes.push_syntax_node(sn))
}
Expression::Row { list, .. } => {
- if let Some(motion_id) = ir_plan.get_motion_from_row(id)? {
+ // In projections with a huge amount of columns it can be
+ // very expensive to retrieve corresponding relational nodes.
+ let rel_ids = ir_plan.get_relational_from_row_nodes(id)?;
+
+ if let Some(motion_id) = ir_plan.get_motion_among_rel_nodes(&rel_ids)? {
// Replace motion node to virtual table node
let vtable = self.plan.get_motion_vtable(motion_id)?.clone();
if vtable.get_alias().is_none() {
@@ -540,7 +544,7 @@ impl<'p> SyntaxPlan<'p> {
}
}
- if let Some(sq_id) = ir_plan.get_sub_query_from_row_node(id)? {
+ if let Some(sq_id) = ir_plan.get_sub_query_among_rel_nodes(&rel_ids)? {
// Replace current row with the referred sub-query
// (except the case when sub-query is located in the FROM clause).
if ir_plan.is_additional_child(sq_id)? {
diff --git a/src/ir/transformation/redistribution.rs b/src/ir/transformation/redistribution.rs
index 9b438db280..369f72d64d 100644
--- a/src/ir/transformation/redistribution.rs
+++ b/src/ir/transformation/redistribution.rs
@@ -136,51 +136,76 @@ impl Plan {
Ok(nodes)
}
- /// Get a sub-query from the row node (if it points to sub-query)
+ /// Get a single sub-query from the row node.
///
/// # Errors
- /// - row contains multiple sub-queries (we don't support this at the moment)
- /// - `relational_map` is not initialized
+ /// - Row node is not of a row type
+ /// There are more than one sub-queries in the row node.
pub fn get_sub_query_from_row_node(
&self,
row_id: usize,
+ ) -> Result<Option<usize>, QueryPlannerError> {
+ let rel_ids = self.get_relational_from_row_nodes(row_id)?;
+ self.get_sub_query_among_rel_nodes(&rel_ids)
+ }
+
+ /// Get a single sub-query from among the list of relational nodes.
+ ///
+ /// # Errors
+ /// - Some of the nodes are not relational
+ /// - There are more than one sub-query
+ pub fn get_sub_query_among_rel_nodes(
+ &self,
+ rel_nodes: &HashSet<usize>,
) -> Result<Option<usize>, QueryPlannerError> {
let mut sq_set: HashSet<usize> = HashSet::new();
- let rel_nodes = self.get_relational_from_row_nodes(row_id)?;
for rel_id in rel_nodes {
- if let Node::Relational(Relational::ScanSubQuery { .. }) = self.get_node(rel_id)? {
- sq_set.insert(rel_id);
+ if let Node::Relational(Relational::ScanSubQuery { .. }) = self.get_node(*rel_id)? {
+ sq_set.insert(*rel_id);
}
}
match sq_set.len().cmp(&1) {
Ordering::Equal => sq_set.iter().next().map_or_else(
|| {
Err(QueryPlannerError::CustomError(format!(
- "Failed to get the first sub-query node from the row: {:?}.",
- self.get_expression_node(row_id)?
+ "Failed to get the first sub-query node from the list of relational nodes: {:?}.",
+ rel_nodes
)))
},
|sq_id| Ok(Some(*sq_id)),
),
Ordering::Less => Ok(None),
Ordering::Greater => Err(QueryPlannerError::CustomError(format!(
- "Found multiple sub-queries in a single row: {:?}.",
- self.get_expression_node(row_id)?
+ "Found multiple sub-queries in a list of relational nodes: {:?}.",
+ rel_nodes
))),
}
}
- /// Extract motion node id from row node
+ /// Extract a motion node id from the row node
///
/// # Errors
- /// - invalid node
+ /// - Row node is not of a row type
+ /// - There are more than one motion nodes in the row node
pub fn get_motion_from_row(&self, node_id: usize) -> Result<Option<usize>, QueryPlannerError> {
let rel_nodes = self.get_relational_from_row_nodes(node_id)?;
+ self.get_motion_among_rel_nodes(&rel_nodes)
+ }
+
+ /// Extract motion node id from row node
+ ///
+ /// # Errors
+ /// - Some of the nodes are not relational
+ /// - There are more than one motion node
+ pub fn get_motion_among_rel_nodes(
+ &self,
+ rel_nodes: &HashSet<usize>,
+ ) -> Result<Option<usize>, QueryPlannerError> {
let mut motion_set: HashSet<usize> = HashSet::new();
for child in rel_nodes {
- if self.get_relation_node(child)?.is_motion() {
- motion_set.insert(child);
+ if self.get_relation_node(*child)?.is_motion() {
+ motion_set.insert(*child);
}
}
@@ -195,7 +220,7 @@ impl Plan {
}
Ordering::Less => Ok(None),
Ordering::Greater => Err(QueryPlannerError::CustomError(
- "Node must contains only once motion".into(),
+ "Node must contain only a single motion".into(),
)),
}
}
--
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