Regenerate all explain files with ClickHouse 25.8

- Updated regenerate-explain command to process tests in parallel
- Added -j flag to control number of workers (default: NumCPU)
- Regenerated all explain.txt files using ClickHouse 25.8.13.73

Author: claude

cmd/regenerate-explain/main.go

@@ -12,8 +12,10 @@ import (
 	"os"
 	"os/exec"
 	"path/filepath"
+	"runtime"
 	"strconv"
 	"strings"
+	"sync"
 	"syscall"
 	"time"
 )
@@ -40,6 +42,7 @@ func main() {
 	dryRun := flag.Bool("dry-run", false, "Print statements without executing")
 	serverOnly := flag.Bool("server", false, "Only ensure server is running, don't regenerate")
 	stopServer := flag.Bool("stop", false, "Stop the ClickHouse server")
+	parallel := flag.Int("j", runtime.NumCPU(), "Number of parallel workers (default: number of CPUs)")
 	flag.Parse()
 
 	// Handle stop command
@@ -85,19 +88,68 @@ func main() {
 		os.Exit(1)
 	}
 
-	var errors []string
-	var processed, skipped int
+	// Collect test directories
+	var testDirs []string
 	for _, entry := range entries {
 		if !entry.IsDir() {
 			continue
 		}
-		testDir := filepath.Join(testdataDir, entry.Name())
-		if err := processTest(testDir, *dryRun); err != nil {
-			if strings.Contains(err.Error(), "no statements found") {
-				skipped++
-				continue
+		testDirs = append(testDirs, filepath.Join(testdataDir, entry.Name()))
+	}
+
+	// Process tests in parallel
+	type result struct {
+		name    string
+		err     error
+		skipped bool
+	}
+
+	numWorkers := *parallel
+	if numWorkers < 1 {
+		numWorkers = 1
+	}
+	fmt.Printf("Processing %d tests with %d workers...\n", len(testDirs), numWorkers)
+
+	jobs := make(chan string, len(testDirs))
+	results := make(chan result, len(testDirs))
+
+	// Start workers
+	var wg sync.WaitGroup
+	for w := 0; w < numWorkers; w++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			for testDir := range jobs {
+				err := processTest(testDir, *dryRun)
+				skipped := err != nil && strings.Contains(err.Error(), "no statements found")
+				if skipped {
+					err = nil
+				}
+				results <- result{name: filepath.Base(testDir), err: err, skipped: skipped}
 			}
-			errors = append(errors, fmt.Sprintf("%s: %v", entry.Name(), err))
+		}()
+	}
+
+	// Send jobs
+	for _, testDir := range testDirs {
+		jobs <- testDir
+	}
+	close(jobs)
+
+	// Wait for workers and close results
+	go func() {
+		wg.Wait()
+		close(results)
+	}()
+
+	// Collect results
+	var errors []string
+	var processed, skipped int
+	for r := range results {
+		if r.skipped {
+			skipped++
+		} else if r.err != nil {
+			errors = append(errors, fmt.Sprintf("%s: %v", r.name, r.err))
 		} else {
 			processed++
 		}
@@ -524,21 +576,26 @@ func processTest(testDir string, dryRun bool) error {
 		return fmt.Errorf("no statements found")
 	}
 
-	fmt.Printf("Processing %s (%d statements)\n", filepath.Base(testDir), len(statements))
+	testName := filepath.Base(testDir)
+
+	if dryRun {
+		fmt.Printf("Processing %s (%d statements)\n", testName, len(statements))
+		for i, stmt := range statements {
+			fmt.Printf("  [%d] %s\n", i+1, truncate(stmt, 80))
+		}
+		return nil
+	}
 
 	// Generate version header comment
 	versionHeader := fmt.Sprintf("-- Generated by ClickHouse %s\n", requiredVersion)
 
+	var stmtErrors []string
 	for i, stmt := range statements {
 		stmtNum := i + 1 // 1-indexed
-		if dryRun {
-			fmt.Printf("  [%d] %s\n", stmtNum, truncate(stmt, 80))
-			continue
-		}
 
 		explain, err := explainAST(stmt)
 		if err != nil {
-			fmt.Printf("  [%d] ERROR: %v\n", stmtNum, err)
+			stmtErrors = append(stmtErrors, fmt.Sprintf("stmt %d: %v", stmtNum, err))
 			// Skip statements that fail - they might be intentionally invalid
 			continue
 		}
@@ -556,7 +613,13 @@ func processTest(testDir string, dryRun bool) error {
 		if err := os.WriteFile(outputPath, []byte(content), 0644); err != nil {
 			return fmt.Errorf("writing %s: %w", outputPath, err)
 		}
-		fmt.Printf("  [%d] -> %s\n", stmtNum, filepath.Base(outputPath))
+	}
+
+	// Print summary
+	if len(stmtErrors) > 0 {
+		fmt.Printf("%s: %d stmts, %d errors\n", testName, len(statements), len(stmtErrors))
+	} else {
+		fmt.Printf("%s: %d stmts OK\n", testName, len(statements))
 	}
 
 	return nil

parser/testdata/00001_count_hits/explain.txt

@@ -1,3 +1,4 @@
+-- Generated by ClickHouse 25.8.13.73
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 2)

parser/testdata/00002_count_visits/explain.txt

@@ -1,3 +1,4 @@
+-- Generated by ClickHouse 25.8.13.73
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 2)

parser/testdata/00002_system_numbers/explain.txt

@@ -1 +1,2 @@
+-- Generated by ClickHouse 25.8.13.73
 Set

parser/testdata/00002_system_numbers/explain_10.txt

@@ -1,3 +1,4 @@
+-- Generated by ClickHouse 25.8.13.73
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 3)

parser/testdata/00002_system_numbers/explain_11.txt

@@ -1,3 +1,4 @@
+-- Generated by ClickHouse 25.8.13.73
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 3)

parser/testdata/00002_system_numbers/explain_12.txt

@@ -1,3 +1,4 @@
+-- Generated by ClickHouse 25.8.13.73
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 3)

parser/testdata/00002_system_numbers/explain_13.txt

@@ -1,3 +1,4 @@
+-- Generated by ClickHouse 25.8.13.73
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 3)

parser/testdata/00002_system_numbers/explain_2.txt

@@ -1,3 +1,4 @@
+-- Generated by ClickHouse 25.8.13.73
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 3)

parser/testdata/00002_system_numbers/explain_3.txt

@@ -1,3 +1,4 @@
+-- Generated by ClickHouse 25.8.13.73
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 4)