⚡ Bolt: replace strings.Builder WriteString(Sprintf) with Fprintf

[srimon12]

💡 What: Replaced builder.WriteString(fmt.Sprintf(...)) with fmt.Fprintf(&builder, ...) across the codebase, particularly in internal/cli/commands/executor.go and internal/dump/dump.go.

🎯 Why: In Go, fmt.Sprintf allocates a new string on the heap. When immediately passed to WriteString, this intermediate string is briefly created and then discarded, creating unnecessary work for the garbage collector. fmt.Fprintf writes directly to the strings.Builder (which implements io.Writer), avoiding this allocation completely.

📊 Impact: Reduces memory allocations during query plan generation and database dumping. Micro-benchmarks typically show a 5-10% speed improvement for formatting and a significant reduction in allocs/op for this specific pattern.

🔬 Measurement: Tested locally via Go benchmark to confirm reduction in allocs/op. All existing unit tests pass via go test ./....

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PR created automatically by Jules for task 13745653911017690048 started by @srimon12

Summary by CodeRabbit

• Refactor
  • Internal performance optimizations to query plan generation and data export operations through improved string handling efficiency.

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ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 10c350df-939c-4797-9dc1-9d929c994235

📥 Commits

Reviewing files that changed from the base of the PR and between 7c85208 and 6a85b0a.

📒 Files selected for processing (3)

• .jules/bolt.md
• internal/cli/commands/executor.go
• internal/dump/dump.go

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📝 Walkthrough

Walkthrough

Replaces builder.WriteString(fmt.Sprintf(...)) with fmt.Fprintf(&builder, ...) across internal/cli/commands/executor.go (all ExplainResult plan output cases) and internal/dump/dump.go (seven call sites spanning INSERT, USING, header comments, map serialization, CREATE COLLECTION, and quantization). Adds a dated note to .jules/bolt.md documenting this pattern.

Changes

fmt.Fprintf String Builder Refactor

Layer / File(s)	Summary
Documentation note for fmt.Fprintf pattern .jules/bolt.md	Adds a 2025-02-28 entry recording the recommendation to use fmt.Fprintf(&builder, ...) over builder.WriteString(fmt.Sprintf(...)).
dump.go fmt.Fprintf refactor internal/dump/dump.go	Switches seven WriteString(fmt.Sprintf(...)) sites to fmt.Fprintf across INSERT INTO … VALUES, USING clause, dump header comments, serializeMap key emission, buildDumpCreateLine vector-type lines, scalar quantile, and turboquant bits sub-clauses.
executor.go ExplainResult fmt.Fprintf refactor internal/cli/commands/executor.go	Converts all WriteString(fmt.Sprintf(...)) calls within ExplainResult's plan builder to fmt.Fprintf across all ast.*Stmt cases: SHOW/CREATE/ALTER/DROP COLLECTION, INSERT, SELECT, SCROLL, and the full QUERY planning path (ORDER BY, SAMPLE, default modes, USING, WITH params, WHERE, OFFSET, SCORE THRESHOLD, LOOKUP, grouping, rerank, recommend/context/discover, CTEs, prefetch, fusion, formula, DELETE, UPDATE, CREATE INDEX).

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Poem

🐇 No more Sprintf in my Write,
I Fprintf direct — what a delight!
Less allocation, less GC fuss,
The builder and I, riding the bus.
Fewer bounces, cleaner hops — ✨

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and specifically describes the main optimization: replacing WriteString(Sprintf) with Fprintf for strings.Builder, which is the primary change across all modified files.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch bolt/optimize-string-builder-formatting-13745653911017690048

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