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Merged
sundy-li merged 1 commit into from
Jan 8, 2026
Merged

refactor(query): reduce string allocations in hot paths #19201

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2 changes: 1 addition & 1 deletion src/query/ast/src/parser/error.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -255,7 +255,7 @@ pub fn display_parser_error(error: Error, source: &str) -> String {
format!("unexpected `{span_text}`")
};
if let Some(suggestion) = has_suggestion {
msg += &format!(". {}", suggestion);
write!(msg, ". {}", suggestion).unwrap();
labels = vec![(inner.span, msg)];

// Return early to skip context labels when we have intelligent suggestions
Expand Down
54 changes: 36 additions & 18 deletions src/query/service/src/physical_plans/format/common.rs
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Expand Up @@ -13,6 +13,7 @@
// limitations under the License.

use std::collections::HashMap;
use std::fmt::Write;

use databend_common_ast::ast::FormatTreeNode;
use databend_common_base::base::format_byte_size;
Expand Down Expand Up @@ -70,64 +71,74 @@ pub fn part_stats_info_to_format_tree(info: &PartStatistics) -> Vec<FormatTreeNo

// range pruning status.
if info.pruning_stats.blocks_range_pruning_before > 0 {
blocks_pruning_description += &format!(
write!(
blocks_pruning_description,
"range pruning: {} to {}{}",
info.pruning_stats.blocks_range_pruning_before,
info.pruning_stats.blocks_range_pruning_after,
format_pruning_cost_suffix(info.pruning_stats.blocks_range_pruning_cost)
);
)
.unwrap();
}

// bloom pruning status.
if info.pruning_stats.blocks_bloom_pruning_before > 0 {
if !blocks_pruning_description.is_empty() {
blocks_pruning_description += ", ";
blocks_pruning_description.push_str(", ");
}
blocks_pruning_description += &format!(
write!(
blocks_pruning_description,
"bloom pruning: {} to {}{}",
info.pruning_stats.blocks_bloom_pruning_before,
info.pruning_stats.blocks_bloom_pruning_after,
format_pruning_cost_suffix(info.pruning_stats.blocks_bloom_pruning_cost)
);
)
.unwrap();
}

// inverted index pruning status.
if info.pruning_stats.blocks_inverted_index_pruning_before > 0 {
if !blocks_pruning_description.is_empty() {
blocks_pruning_description += ", ";
blocks_pruning_description.push_str(", ");
}
blocks_pruning_description += &format!(
write!(
blocks_pruning_description,
"inverted pruning: {} to {}{}",
info.pruning_stats.blocks_inverted_index_pruning_before,
info.pruning_stats.blocks_inverted_index_pruning_after,
format_pruning_cost_suffix(info.pruning_stats.blocks_inverted_index_pruning_cost)
);
)
.unwrap();
}

// topn pruning status.
if info.pruning_stats.blocks_topn_pruning_before > 0 {
if !blocks_pruning_description.is_empty() {
blocks_pruning_description += ", ";
blocks_pruning_description.push_str(", ");
}
blocks_pruning_description += &format!(
write!(
blocks_pruning_description,
"topn pruning: {} to {}{}",
info.pruning_stats.blocks_topn_pruning_before,
info.pruning_stats.blocks_topn_pruning_after,
format_pruning_cost_suffix(info.pruning_stats.blocks_topn_pruning_cost)
);
)
.unwrap();
}

// vector index pruning status.
if info.pruning_stats.blocks_vector_index_pruning_before > 0 {
if !blocks_pruning_description.is_empty() {
blocks_pruning_description += ", ";
blocks_pruning_description.push_str(", ");
}
blocks_pruning_description += &format!(
write!(
blocks_pruning_description,
"vector pruning: {} to {}{}",
info.pruning_stats.blocks_vector_index_pruning_before,
info.pruning_stats.blocks_vector_index_pruning_after,
format_pruning_cost_suffix(info.pruning_stats.blocks_vector_index_pruning_cost)
);
)
.unwrap();
}

// Combine segment pruning and blocks pruning descriptions if any
Expand All @@ -137,19 +148,26 @@ pub fn part_stats_info_to_format_tree(info: &PartStatistics) -> Vec<FormatTreeNo
let mut pruning_description = String::new();

if info.pruning_stats.segments_range_pruning_before > 0 {
pruning_description += &format!(
write!(
pruning_description,
"segments: <range pruning: {} to {}{}>",
info.pruning_stats.segments_range_pruning_before,
info.pruning_stats.segments_range_pruning_after,
format_pruning_cost_suffix(info.pruning_stats.segments_range_pruning_cost)
);
)
.unwrap();
}

if !blocks_pruning_description.is_empty() {
if !pruning_description.is_empty() {
pruning_description += ", ";
pruning_description.push_str(", ");
}
pruning_description += &format!("blocks: <{}>", blocks_pruning_description);
write!(
pruning_description,
"blocks: <{}>",
blocks_pruning_description
)
.unwrap();
}

items.push(FormatTreeNode::new(format!(
Expand Down
61 changes: 38 additions & 23 deletions src/query/sql/src/planner/optimizer/pipeline/trace/trace.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -13,6 +13,7 @@
// limitations under the License.

use std::collections::BTreeMap;
use std::fmt::Write;
use std::time::Duration;

use databend_common_exception::Result;
Expand Down Expand Up @@ -286,10 +287,12 @@ impl OptimizerTraceCollector {
(0, 0)
};

summary.push_str(&format!(
"[{}] {}: {} ({:.2?})\n",
writeln!(
summary,
"[{}] {}: {} ({:.2?})",
status_symbol, optimizer.index, optimizer.name, optimizer.time
));
)
.unwrap();

if total_rules > 0 {
let applied_percentage = if total_rules > 0 {
Expand All @@ -298,10 +301,12 @@ impl OptimizerTraceCollector {
0
};

summary.push_str(&format!(
" └── Rules: {}/{} Applied ({}%)\n",
writeln!(
summary,
" └── Rules: {}/{} Applied ({}%)",
applied_rules, total_rules, applied_percentage
));
)
.unwrap();

// Add detailed rules summary if available
if let Some(optimizer_rules) = rules.get(&optimizer.name) {
Expand All @@ -312,7 +317,7 @@ impl OptimizerTraceCollector {
// Add indentation to rules summary
for line in rules_summary.lines() {
if !line.trim().is_empty() {
summary.push_str(&format!(" {}\n", line));
writeln!(summary, " {}", line).unwrap();
}
}
}
Expand Down Expand Up @@ -340,16 +345,18 @@ impl OptimizerTraceCollector {
let mut detail = String::new();

// Add basic optimizer information
detail.push_str(&format!(
write!(
detail,
"[{}] {}: {} ({:.2?})\n\n",
status_symbol, optimizer.index, optimizer.name, optimizer.time
));
)
.unwrap();

// Add expression changes if any
if optimizer.had_effect && !optimizer.diff.is_empty() {
detail.push_str(" Changes:\n");
for line in optimizer.diff.lines() {
detail.push_str(&format!(" {}\n", line));
writeln!(detail, " {}", line).unwrap();
}
detail.push('\n');
}
Expand Down Expand Up @@ -389,15 +396,17 @@ impl OptimizerTraceCollector {
return report;
}

report.push_str(&format!("[{}] Rules Summary:\n", optimizer.name));
writeln!(report, "[{}] Rules Summary:", optimizer.name).unwrap();

// List all rules with their status
for rule in &all_rules {
let status_symbol = if rule.had_effect { "✓" } else { "✗" };
report.push_str(&format!(
" [{}] {}.{}: {} ({:.2?})\n",
writeln!(
report,
" [{}] {}.{}: {} ({:.2?})",
status_symbol, optimizer.index, rule.sequence, rule.name, rule.time
));
)
.unwrap();
}
report.push('\n');

Expand All @@ -418,17 +427,21 @@ impl OptimizerTraceCollector {
};

// Add statistics to report
report.push_str(&format!(
" Total Applied Rules: {}/{} ({}%)\n",
writeln!(
report,
" Total Applied Rules: {}/{} ({}%)",
applied_rules, total_rules, applied_percentage
));
)
.unwrap();

report.push_str(&format!(
write!(
report,
" Total Non-Applied Rules: {}/{} ({}%)\n\n",
total_rules - applied_rules,
total_rules,
non_applied_percentage
));
)
.unwrap();

report
}
Expand All @@ -454,16 +467,18 @@ impl OptimizerTraceCollector {
for rule in applied_rules {
// Always use checkmark since we only show rules that had an effect
let status_symbol = "✓";
report.push_str(&format!(
" [{}] {}.{}: {}.{} ({:.2?})\n",
writeln!(
report,
" [{}] {}.{}: {}.{} ({:.2?})",
status_symbol, optimizer.index, rule.sequence, optimizer.name, rule.name, rule.time
));
)
.unwrap();

// Add expression changes if available
if !rule.diff.is_empty() {
report.push_str(" Changes:\n");
for line in rule.diff.lines() {
report.push_str(&format!(" {}\n", line));
writeln!(report, " {}", line).unwrap();
}
}

Expand Down
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