Add KILL QUERY SETTINGS support and fix operator mapping

- Add Settings field to KillQuery struct
- Parse SETTINGS clause for KILL QUERY/MUTATION statements
- Map comparison operators to function names in EXPLAIN output
  (e.g., = becomes equals, != becomes notEquals)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: kyleconroy

ast/ast.go

@@ -1069,6 +1069,7 @@ type KillQuery struct {
 	Sync     bool           `json:"sync,omitempty"`    // SYNC mode (default false = ASYNC)
 	Test     bool           `json:"test,omitempty"`    // TEST mode
 	Format   string         `json:"format,omitempty"`  // FORMAT clause
+	Settings []*SettingExpr `json:"settings,omitempty"`
 }
 
 func (k *KillQuery) Pos() token.Position { return k.Position }

internal/explain/statements.go

@@ -2391,7 +2391,23 @@ func explainKillQuery(sb *strings.Builder, n *ast.KillQuery, indent string, dept
 	if n.Where != nil {
 		switch expr := n.Where.(type) {
 		case *ast.BinaryExpr:
-			funcName = "Function_" + strings.ToLower(expr.Op)
+			// Map operators to function names
+			opName := strings.ToLower(expr.Op)
+			switch opName {
+			case "=":
+				opName = "equals"
+			case "!=", "<>":
+				opName = "notEquals"
+			case "<":
+				opName = "less"
+			case "<=":
+				opName = "lessOrEquals"
+			case ">":
+				opName = "greater"
+			case ">=":
+				opName = "greaterOrEquals"
+			}
+			funcName = "Function_" + opName
 		case *ast.FunctionCall:
 			funcName = "Function_" + expr.Name
 		default:
@@ -2407,14 +2423,17 @@ func explainKillQuery(sb *strings.Builder, n *ast.KillQuery, indent string, dept
 		mode = "TEST"
 	}
 
-	// Count children: WHERE expression + FORMAT identifier
+	// Count children: WHERE expression + FORMAT identifier + Settings
 	children := 0
 	if n.Where != nil {
 		children++
 	}
 	if n.Format != "" {
 		children++
 	}
+	if len(n.Settings) > 0 {
+		children++
+	}
 
 	// Header: KillQueryQuery Function_xxx MODE (children N)
 	if funcName != "" {
@@ -2432,6 +2451,11 @@ func explainKillQuery(sb *strings.Builder, n *ast.KillQuery, indent string, dept
 	if n.Format != "" {
 		fmt.Fprintf(sb, "%s Identifier %s\n", indent, n.Format)
 	}
+
+	// Output Settings
+	if len(n.Settings) > 0 {
+		fmt.Fprintf(sb, "%s Set\n", indent)
+	}
 }
 
 func explainCheckQuery(sb *strings.Builder, n *ast.CheckQuery, indent string) {

parser/parser.go

@@ -8380,6 +8380,12 @@ endModifiers:
 		}
 	}
 
+	// Parse SETTINGS clause
+	if p.currentIs(token.SETTINGS) {
+		p.nextToken() // skip SETTINGS
+		query.Settings = p.parseSettingsList()
+	}
+
 	return query
 }
 

parser/testdata/02494_query_cache_eligible_queries/metadata.json

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