Add DROP access control statement support in EXPLAIN output

Added proper parsing and EXPLAIN output for:
- DROP ROLE
- DROP QUOTA
- DROP POLICY
- DROP ROW POLICY
- DROP SETTINGS PROFILE

These statements now output their expected EXPLAIN format like
"DROP ROLE query" instead of being treated as table drops.

Author: claude

ast/ast.go

@@ -468,19 +468,24 @@ func (t *TTLClause) End() token.Position { return t.Position }
 
 // DropQuery represents a DROP statement.
 type DropQuery struct {
-	Position     token.Position     `json:"-"`
-	IfExists     bool               `json:"if_exists,omitempty"`
-	Database     string             `json:"database,omitempty"`
-	Table        string             `json:"table,omitempty"`
-	Tables       []*TableIdentifier `json:"tables,omitempty"` // For DROP TABLE t1, t2, t3
-	View         string             `json:"view,omitempty"`
-	User         string             `json:"user,omitempty"`
-	Function     string             `json:"function,omitempty"`   // For DROP FUNCTION
-	Dictionary   string             `json:"-"` // For DROP DICTIONARY (format only, not in AST JSON)
-	Temporary    bool               `json:"temporary,omitempty"`
-	OnCluster    string             `json:"on_cluster,omitempty"`
-	DropDatabase bool               `json:"drop_database,omitempty"`
-	Sync         bool               `json:"sync,omitempty"`
+	Position        token.Position     `json:"-"`
+	IfExists        bool               `json:"if_exists,omitempty"`
+	Database        string             `json:"database,omitempty"`
+	Table           string             `json:"table,omitempty"`
+	Tables          []*TableIdentifier `json:"tables,omitempty"` // For DROP TABLE t1, t2, t3
+	View            string             `json:"view,omitempty"`
+	User            string             `json:"user,omitempty"`
+	Function        string             `json:"function,omitempty"` // For DROP FUNCTION
+	Dictionary      string             `json:"-"`                  // For DROP DICTIONARY (format only, not in AST JSON)
+	Role            string             `json:"role,omitempty"`     // For DROP ROLE
+	Quota           string             `json:"quota,omitempty"`    // For DROP QUOTA
+	Policy          string             `json:"policy,omitempty"`   // For DROP POLICY
+	RowPolicy       string             `json:"row_policy,omitempty"` // For DROP ROW POLICY
+	SettingsProfile string             `json:"settings_profile,omitempty"` // For DROP SETTINGS PROFILE
+	Temporary       bool               `json:"temporary,omitempty"`
+	OnCluster       string             `json:"on_cluster,omitempty"`
+	DropDatabase    bool               `json:"drop_database,omitempty"`
+	Sync            bool               `json:"sync,omitempty"`
 }
 
 func (d *DropQuery) Pos() token.Position { return d.Position }

internal/explain/statements.go

@@ -415,6 +415,36 @@ func explainDropQuery(sb *strings.Builder, n *ast.DropQuery, indent string, dept
 		return
 	}
 
+	// DROP ROLE
+	if n.Role != "" {
+		fmt.Fprintf(sb, "%sDROP ROLE query\n", indent)
+		return
+	}
+
+	// DROP QUOTA
+	if n.Quota != "" {
+		fmt.Fprintf(sb, "%sDROP QUOTA query\n", indent)
+		return
+	}
+
+	// DROP POLICY
+	if n.Policy != "" {
+		fmt.Fprintf(sb, "%sDROP POLICY query\n", indent)
+		return
+	}
+
+	// DROP ROW POLICY
+	if n.RowPolicy != "" {
+		fmt.Fprintf(sb, "%sDROP ROW POLICY query\n", indent)
+		return
+	}
+
+	// DROP SETTINGS PROFILE
+	if n.SettingsProfile != "" {
+		fmt.Fprintf(sb, "%sDROP SETTINGS PROFILE query\n", indent)
+		return
+	}
+
 	// Handle multiple tables: DROP TABLE t1, t2, t3
 	if len(n.Tables) > 1 {
 		fmt.Fprintf(sb, "%sDropQuery   (children %d)\n", indent, 1)

parser/parser.go

@@ -3268,6 +3268,7 @@ func (p *Parser) parseDrop() *ast.DropQuery {
 		if p.currentIs(token.IDENT) && strings.ToUpper(p.current.Value) == "PROFILE" {
 			p.nextToken()
 		}
+		drop.SettingsProfile = "_pending_"
 	default:
 		// Handle multi-word DROP types: ROW POLICY, NAMED COLLECTION, DICTIONARY
 		if p.currentIs(token.IDENT) {
@@ -3276,8 +3277,26 @@ func (p *Parser) parseDrop() *ast.DropQuery {
 			case "DICTIONARY":
 				dropDictionary = true
 				p.nextToken()
-			case "ROW", "NAMED", "POLICY", "QUOTA", "ROLE":
-				// Skip the DROP type tokens
+			case "ROW":
+				// DROP ROW POLICY
+				p.nextToken() // skip ROW
+				if p.currentIs(token.IDENT) && strings.ToUpper(p.current.Value) == "POLICY" {
+					p.nextToken() // skip POLICY
+				}
+				// Mark as row policy drop - name will be set later
+				drop.RowPolicy = "_pending_"
+			case "POLICY":
+				// DROP POLICY
+				p.nextToken()
+				drop.Policy = "_pending_"
+			case "QUOTA":
+				p.nextToken()
+				drop.Quota = "_pending_"
+			case "ROLE":
+				p.nextToken()
+				drop.Role = "_pending_"
+			case "NAMED":
+				// DROP NAMED COLLECTION - skip tokens
 				for p.currentIs(token.IDENT) || p.current.Token.IsKeyword() {
 					if p.currentIs(token.IF) {
 						break // Hit IF EXISTS
@@ -3326,6 +3345,16 @@ func (p *Parser) parseDrop() *ast.DropQuery {
 			}
 		} else if dropFunction {
 			drop.Function = tableName
+		} else if drop.Role == "_pending_" {
+			drop.Role = tableName
+		} else if drop.Quota == "_pending_" {
+			drop.Quota = tableName
+		} else if drop.Policy == "_pending_" {
+			drop.Policy = tableName
+		} else if drop.RowPolicy == "_pending_" {
+			drop.RowPolicy = tableName
+		} else if drop.SettingsProfile == "_pending_" {
+			drop.SettingsProfile = tableName
 		} else if dropDictionary {
 			drop.Dictionary = tableName
 			// Also set Table/Tables for backward compatibility with AST JSON

parser/testdata/01702_system_query_log/metadata.json

@@ -37,8 +37,6 @@
     "stmt60": true,
     "stmt68": true,
     "stmt69": true,
-    "stmt74": true,
-    "stmt8": true,
-    "stmt86": true
+    "stmt74": true
   }
 }