From dbfcdbba1297553dceb43feec222893b0324d04b Mon Sep 17 00:00:00 2001
From: Denis Smirnov <sd@picodata.io>
Date: Fri, 15 Apr 2022 18:14:39 +0700
Subject: [PATCH] perf: improve performance in new_columns() function
---
src/ir/expression.rs | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/src/ir/expression.rs b/src/ir/expression.rs
index f3fa56b01e..0123e7009f 100644
--- a/src/ir/expression.rs
+++ b/src/ir/expression.rs
@@ -318,8 +318,8 @@ impl Plan {
)));
}
}
-
- let mut result: Vec<usize> = Vec::with_capacity(col_names.len());
+
+ let mut result: Vec<usize> = Vec::new();
if col_names.is_empty() {
let required_targets = if is_join { targets } else { &targets[0..1] };
@@ -353,7 +353,7 @@ impl Plan {
} else {
return Err(QueryPlannerError::InvalidRelation);
};
-
+ result.reserve(child_row_list.len());
for (pos, alias_node) in child_row_list.iter().enumerate() {
let name: String =
if let Node::Expression(Expression::Alias { ref name, .. }) =
@@ -387,6 +387,7 @@ impl Plan {
return Ok(result);
}
+ result.reserve(col_names.len());
let target_child: usize = if let Some(target) = targets.get(0) {
*target
} else {
@@ -400,6 +401,10 @@ impl Plan {
));
};
+ let mut col_names_set: HashSet<&str> = HashSet::with_capacity(col_names.len());
+ for col_name in col_names {
+ col_names_set.insert(col_name);
+ }
let map: HashMap<&str, usize, RandomState> =
if let Node::Relational(relational_op) = self.get_node(child_node)? {
let output_id = relational_op.output();
@@ -407,10 +412,13 @@ impl Plan {
if let Expression::Row { list, .. } = output {
let state = RandomState::new();
let mut map: HashMap<&str, usize, RandomState> =
- HashMap::with_capacity_and_hasher(list.len(), state);
+ HashMap::with_capacity_and_hasher(col_names.len(), state);
for (pos, col_id) in list.iter().enumerate() {
let alias = self.get_expression_node(*col_id)?;
if let Expression::Alias { ref name, .. } = alias {
+ if !col_names_set.contains(&name.as_str()) {
+ continue;
+ }
if map.insert(name, pos).is_some() {
return Err(QueryPlannerError::CustomError(format!(
"Duplicate column name {} at position {}",
--
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