Fix multiple EXPLAIN output formatting issues

This commit fixes several EXPLAIN AST output issues:

1. SampleRatio formatting: Convert decimal ratios like 0.1 to fractions
   like 1/10 to match ClickHouse EXPLAIN AST output

2. CHECK TABLE FORMAT clause: Add support for parsing and outputting the
   FORMAT clause in CHECK TABLE statements

3. Materialized view ViewTargets: For CREATE MATERIALIZED VIEW statements,
   output the AS SELECT clause before the storage definition and wrap
   storage definition in ViewTargets

4. OPTIMIZE TABLE PARTITION: Add support for outputting the PARTITION
   clause in OPTIMIZE TABLE statements

These fixes resolve 44 test statements across many test files.

Author: claude

ast/ast.go

@@ -720,6 +720,7 @@ type CheckQuery struct {
 	Position  token.Position `json:"-"`
 	Database  string         `json:"database,omitempty"`
 	Table     string         `json:"table"`
+	Format    string         `json:"format,omitempty"`
 	Settings  []*SettingExpr `json:"settings,omitempty"`
 }
 

internal/explain/explain.go

@@ -144,7 +144,7 @@ func Node(sb *strings.Builder, node interface{}, depth int) {
 	case *ast.AlterQuery:
 		explainAlterQuery(sb, n, indent, depth)
 	case *ast.OptimizeQuery:
-		explainOptimizeQuery(sb, n, indent)
+		explainOptimizeQuery(sb, n, indent, depth)
 	case *ast.TruncateQuery:
 		explainTruncateQuery(sb, n, indent)
 	case *ast.CheckQuery:

internal/explain/statements.go

@@ -192,7 +192,12 @@ func explainCreateQuery(sb *strings.Builder, n *ast.CreateQuery, indent string,
 			}
 		}
 	}
-	if n.Engine != nil || len(n.OrderBy) > 0 || len(n.PrimaryKey) > 0 || n.PartitionBy != nil || n.SampleBy != nil || n.TTL != nil || len(n.Settings) > 0 {
+	// For materialized views, output AsSelect before storage definition
+	if n.Materialized && n.AsSelect != nil {
+		Node(sb, n.AsSelect, depth+1)
+	}
+	hasStorage := n.Engine != nil || len(n.OrderBy) > 0 || len(n.PrimaryKey) > 0 || n.PartitionBy != nil || n.SampleBy != nil || n.TTL != nil || len(n.Settings) > 0
+	if hasStorage {
 		storageChildren := 0
 		if n.Engine != nil {
 			storageChildren++
@@ -231,80 +236,91 @@ func explainCreateQuery(sb *strings.Builder, n *ast.CreateQuery, indent string,
 		if len(n.Settings) > 0 {
 			storageChildren++
 		}
-		fmt.Fprintf(sb, "%s Storage definition (children %d)\n", indent, storageChildren)
+		// For materialized views, wrap storage definition in ViewTargets
+		// and use extra indentation for storage children
+		storageIndent := indent + " " // 1 space for regular storage (format strings add 1 more)
+		storageChildDepth := depth + 2
+		if n.Materialized {
+			fmt.Fprintf(sb, "%s ViewTargets (children %d)\n", indent, 1)
+			fmt.Fprintf(sb, "%s  Storage definition (children %d)\n", indent, storageChildren)
+			storageIndent = indent + "  " // 2 spaces for materialized (format strings add 1 more = 3 total)
+			storageChildDepth = depth + 3
+		} else {
+			fmt.Fprintf(sb, "%s Storage definition (children %d)\n", indent, storageChildren)
+		}
 		if n.Engine != nil {
 			if n.Engine.HasParentheses {
-				fmt.Fprintf(sb, "%s  Function %s (children %d)\n", indent, n.Engine.Name, 1)
+				fmt.Fprintf(sb, "%s Function %s (children %d)\n", storageIndent, n.Engine.Name, 1)
 				if len(n.Engine.Parameters) > 0 {
-					fmt.Fprintf(sb, "%s   ExpressionList (children %d)\n", indent, len(n.Engine.Parameters))
+					fmt.Fprintf(sb, "%s  ExpressionList (children %d)\n", storageIndent, len(n.Engine.Parameters))
 					for _, param := range n.Engine.Parameters {
-						Node(sb, param, depth+4)
+						Node(sb, param, storageChildDepth+2)
 					}
 				} else {
-					fmt.Fprintf(sb, "%s   ExpressionList\n", indent)
+					fmt.Fprintf(sb, "%s  ExpressionList\n", storageIndent)
 				}
 			} else {
-				fmt.Fprintf(sb, "%s  Function %s\n", indent, n.Engine.Name)
+				fmt.Fprintf(sb, "%s Function %s\n", storageIndent, n.Engine.Name)
 			}
 		}
 		if n.PartitionBy != nil {
 			if ident, ok := n.PartitionBy.(*ast.Identifier); ok {
-				fmt.Fprintf(sb, "%s  Identifier %s\n", indent, ident.Name())
+				fmt.Fprintf(sb, "%s Identifier %s\n", storageIndent, ident.Name())
 			} else {
-				Node(sb, n.PartitionBy, depth+2)
+				Node(sb, n.PartitionBy, storageChildDepth)
 			}
 		}
 		if len(n.OrderBy) > 0 {
 			if len(n.OrderBy) == 1 {
 				if ident, ok := n.OrderBy[0].(*ast.Identifier); ok {
-					fmt.Fprintf(sb, "%s  Identifier %s\n", indent, ident.Name())
+					fmt.Fprintf(sb, "%s Identifier %s\n", storageIndent, ident.Name())
 				} else if lit, ok := n.OrderBy[0].(*ast.Literal); ok && lit.Type == ast.LiteralTuple {
 					// Handle tuple literal (including empty tuple from ORDER BY ())
 					exprs, _ := lit.Value.([]ast.Expression)
-					fmt.Fprintf(sb, "%s  Function tuple (children %d)\n", indent, 1)
+					fmt.Fprintf(sb, "%s Function tuple (children %d)\n", storageIndent, 1)
 					if len(exprs) > 0 {
-						fmt.Fprintf(sb, "%s   ExpressionList (children %d)\n", indent, len(exprs))
+						fmt.Fprintf(sb, "%s  ExpressionList (children %d)\n", storageIndent, len(exprs))
 						for _, e := range exprs {
-							Node(sb, e, depth+4)
+							Node(sb, e, storageChildDepth+2)
 						}
 					} else {
-						fmt.Fprintf(sb, "%s   ExpressionList\n", indent)
+						fmt.Fprintf(sb, "%s  ExpressionList\n", storageIndent)
 					}
 				} else {
-					Node(sb, n.OrderBy[0], depth+2)
+					Node(sb, n.OrderBy[0], storageChildDepth)
 				}
 			} else {
-				fmt.Fprintf(sb, "%s  Function tuple (children %d)\n", indent, 1)
-				fmt.Fprintf(sb, "%s   ExpressionList (children %d)\n", indent, len(n.OrderBy))
+				fmt.Fprintf(sb, "%s Function tuple (children %d)\n", storageIndent, 1)
+				fmt.Fprintf(sb, "%s  ExpressionList (children %d)\n", storageIndent, len(n.OrderBy))
 				for _, o := range n.OrderBy {
-					Node(sb, o, depth+4)
+					Node(sb, o, storageChildDepth+2)
 				}
 			}
 		}
 		if len(n.PrimaryKey) > 0 {
 			if len(n.PrimaryKey) == 1 {
 				if ident, ok := n.PrimaryKey[0].(*ast.Identifier); ok {
-					fmt.Fprintf(sb, "%s  Identifier %s\n", indent, ident.Name())
+					fmt.Fprintf(sb, "%s Identifier %s\n", storageIndent, ident.Name())
 				} else if lit, ok := n.PrimaryKey[0].(*ast.Literal); ok && lit.Type == ast.LiteralTuple {
 					// Handle tuple literal (including empty tuple from PRIMARY KEY ())
 					exprs, _ := lit.Value.([]ast.Expression)
-					fmt.Fprintf(sb, "%s  Function tuple (children %d)\n", indent, 1)
+					fmt.Fprintf(sb, "%s Function tuple (children %d)\n", storageIndent, 1)
 					if len(exprs) > 0 {
-						fmt.Fprintf(sb, "%s   ExpressionList (children %d)\n", indent, len(exprs))
+						fmt.Fprintf(sb, "%s  ExpressionList (children %d)\n", storageIndent, len(exprs))
 						for _, e := range exprs {
-							Node(sb, e, depth+4)
+							Node(sb, e, storageChildDepth+2)
 						}
 					} else {
-						fmt.Fprintf(sb, "%s   ExpressionList\n", indent)
+						fmt.Fprintf(sb, "%s  ExpressionList\n", storageIndent)
 					}
 				} else {
-					Node(sb, n.PrimaryKey[0], depth+2)
+					Node(sb, n.PrimaryKey[0], storageChildDepth)
 				}
 			} else {
-				fmt.Fprintf(sb, "%s  Function tuple (children %d)\n", indent, 1)
-				fmt.Fprintf(sb, "%s   ExpressionList (children %d)\n", indent, len(n.PrimaryKey))
+				fmt.Fprintf(sb, "%s Function tuple (children %d)\n", storageIndent, 1)
+				fmt.Fprintf(sb, "%s  ExpressionList (children %d)\n", storageIndent, len(n.PrimaryKey))
 				for _, p := range n.PrimaryKey {
-					Node(sb, p, depth+4)
+					Node(sb, p, storageChildDepth+2)
 				}
 			}
 		}
@@ -323,20 +339,21 @@ func explainCreateQuery(sb *strings.Builder, n *ast.CreateQuery, indent string,
 					}
 				}
 				if showSampleBy {
-					Node(sb, n.SampleBy, depth+2)
+					Node(sb, n.SampleBy, storageChildDepth)
 				}
 			}
 		}
 		if n.TTL != nil {
-			fmt.Fprintf(sb, "%s  ExpressionList (children 1)\n", indent)
-			fmt.Fprintf(sb, "%s   TTLElement (children 1)\n", indent)
-			Node(sb, n.TTL.Expression, depth+4)
+			fmt.Fprintf(sb, "%s ExpressionList (children 1)\n", storageIndent)
+			fmt.Fprintf(sb, "%s  TTLElement (children 1)\n", storageIndent)
+			Node(sb, n.TTL.Expression, storageChildDepth+2)
 		}
 		if len(n.Settings) > 0 {
-			fmt.Fprintf(sb, "%s  Set\n", indent)
+			fmt.Fprintf(sb, "%s Set\n", storageIndent)
 		}
 	}
-	if n.AsSelect != nil {
+	// For non-materialized views, output AsSelect after storage
+	if n.AsSelect != nil && !n.Materialized {
 		// AS SELECT is output directly without Subquery wrapper
 		Node(sb, n.AsSelect, depth+1)
 	}
@@ -908,7 +925,7 @@ func countAlterCommandChildren(cmd *ast.AlterCommand) int {
 	return children
 }
 
-func explainOptimizeQuery(sb *strings.Builder, n *ast.OptimizeQuery, indent string) {
+func explainOptimizeQuery(sb *strings.Builder, n *ast.OptimizeQuery, indent string, depth int) {
 	if n == nil {
 		fmt.Fprintf(sb, "%s*ast.OptimizeQuery\n", indent)
 		return
@@ -919,7 +936,16 @@ func explainOptimizeQuery(sb *strings.Builder, n *ast.OptimizeQuery, indent stri
 		name += "_final"
 	}
 
-	fmt.Fprintf(sb, "%sOptimizeQuery  %s (children %d)\n", indent, name, 1)
+	children := 1 // identifier
+	if n.Partition != nil {
+		children++
+	}
+
+	fmt.Fprintf(sb, "%sOptimizeQuery  %s (children %d)\n", indent, name, children)
+	if n.Partition != nil {
+		fmt.Fprintf(sb, "%s Partition (children 1)\n", indent)
+		Node(sb, n.Partition, depth+2)
+	}
 	fmt.Fprintf(sb, "%s Identifier %s\n", indent, n.Table)
 }
 
@@ -950,12 +976,18 @@ func explainCheckQuery(sb *strings.Builder, n *ast.CheckQuery, indent string) {
 	}
 
 	children := 1 // identifier
+	if n.Format != "" {
+		children++
+	}
 	if len(n.Settings) > 0 {
 		children++
 	}
 
 	fmt.Fprintf(sb, "%sCheckQuery  %s (children %d)\n", indent, name, children)
 	fmt.Fprintf(sb, "%s Identifier %s\n", indent, name)
+	if n.Format != "" {
+		fmt.Fprintf(sb, "%s Identifier %s\n", indent, n.Format)
+	}
 	if len(n.Settings) > 0 {
 		fmt.Fprintf(sb, "%s Set\n", indent)
 	}

internal/explain/tables.go

@@ -91,7 +91,13 @@ func formatSampleRatioOperand(sb *strings.Builder, expr ast.Expression) {
 		case uint64:
 			fmt.Fprintf(sb, "%d", v)
 		case float64:
-			fmt.Fprintf(sb, "%g", v)
+			// Convert decimal to fraction for EXPLAIN AST output
+			// ClickHouse shows 0.1 as "1 / 10", 0.01 as "1 / 100", etc.
+			if frac := floatToFraction(v); frac != "" {
+				sb.WriteString(frac)
+			} else {
+				fmt.Fprintf(sb, "%g", v)
+			}
 		default:
 			fmt.Fprintf(sb, "%v", v)
 		}
@@ -100,6 +106,32 @@ func formatSampleRatioOperand(sb *strings.Builder, expr ast.Expression) {
 	}
 }
 
+// floatToFraction converts a float to a fraction string like "1 / 10"
+// Returns empty string if the float can't be reasonably converted to a simple fraction
+func floatToFraction(f float64) string {
+	if f <= 0 || f >= 1 {
+		return ""
+	}
+	// Try common denominators
+	denominators := []int64{2, 3, 4, 5, 8, 10, 16, 20, 25, 32, 50, 64, 100, 128, 1000, 10000, 100000, 1000000}
+	for _, denom := range denominators {
+		num := f * float64(denom)
+		// Check if num is close to an integer
+		rounded := int64(num + 0.5)
+		if rounded > 0 && abs(num-float64(rounded)) < 1e-9 {
+			return fmt.Sprintf("%d / %d", rounded, denom)
+		}
+	}
+	return ""
+}
+
+func abs(x float64) float64 {
+	if x < 0 {
+		return -x
+	}
+	return x
+}
+
 // explainViewExplain handles EXPLAIN queries used as table sources, converting to viewExplain function
 func explainViewExplain(sb *strings.Builder, n *ast.ExplainQuery, alias string, indent string, depth int) {
 	// When EXPLAIN is used as a table source, it becomes viewExplain function

parser/parser.go

@@ -3754,6 +3754,12 @@ func (p *Parser) parseCheck() *ast.CheckQuery {
 		check.Table = tableName
 	}
 
+	// Parse optional FORMAT
+	if p.currentIs(token.FORMAT) {
+		p.nextToken() // skip FORMAT
+		check.Format = p.parseIdentifierName()
+	}
+
 	// Parse optional SETTINGS
 	if p.currentIs(token.SETTINGS) {
 		p.nextToken() // skip SETTINGS

parser/testdata/00040_aggregating_materialized_view/metadata.json

@@ -1,5 +1 @@
-{
-  "explain_todo": {
-    "stmt3": true
-  }
-}
+{}

parser/testdata/00041_aggregating_materialized_view/metadata.json

@@ -1,5 +1 @@
-{
-  "explain_todo": {
-    "stmt5": true
-  }
-}
+{}

parser/testdata/00056_view/metadata.json

@@ -1 +1 @@
-{"explain_todo":{"stmt6":true}}
+{}

parser/testdata/00063_check_query/metadata.json

@@ -1,5 +1 @@
-{
-  "explain_todo": {
-    "stmt9": true
-  }
-}
+{}

parser/testdata/00084_summing_merge_tree/metadata.json

@@ -1,5 +1 @@
-{
-  "explain_todo": {
-    "stmt25": true
-  }
-}
+{}