diff --git a/src/main/kotlin/kestrel/engine/SelectRunner.kt b/src/main/kotlin/kestrel/engine/SelectRunner.kt
index 6ce7ac9..39ead65 100644
--- a/src/main/kotlin/kestrel/engine/SelectRunner.kt
+++ b/src/main/kotlin/kestrel/engine/SelectRunner.kt
@@ -2,34 +2,76 @@ package kestrel.engine
 
 import kestrel.KestrelException
 import kestrel.catalog.Catalog
+import kestrel.catalog.Column
 import kestrel.catalog.TableSchema
+import kestrel.sql.ast.BetweenExpression
 import kestrel.sql.ast.BinaryExpression
 import kestrel.sql.ast.BinaryOperator
+import kestrel.sql.ast.CallExpression
+import kestrel.sql.ast.CaseExpression
+import kestrel.sql.ast.CastExpression
+import kestrel.sql.ast.CollateExpression
 import kestrel.sql.ast.ColumnExpression
+import kestrel.sql.ast.CommonTableExpression
+import kestrel.sql.ast.CurrentValueExpression
+import kestrel.sql.ast.ExistsExpression
 import kestrel.sql.ast.Expression
 import kestrel.sql.ast.ExpressionProjection
+import kestrel.sql.ast.FrameBound
+import kestrel.sql.ast.FrameBoundType
+import kestrel.sql.ast.FrameExclude
+import kestrel.sql.ast.FrameUnit
+import kestrel.sql.ast.FromItem
 import kestrel.sql.ast.FunctionExpression
+import kestrel.sql.ast.InExpression
+import kestrel.sql.ast.InSubqueryExpression
+import kestrel.sql.ast.IsNullExpression
 import kestrel.sql.ast.JoinClause
 import kestrel.sql.ast.JoinType
+import kestrel.sql.ast.LikeExpression
 import kestrel.sql.ast.LiteralExpression
+import kestrel.sql.ast.MergeActionExpression
+import kestrel.sql.ast.NextValueExpression
+import kestrel.sql.ast.ParameterExpression
+import kestrel.sql.ast.OrderKey
+import kestrel.sql.ast.QueryStatement
+import kestrel.sql.ast.ScalarSubqueryExpression
 import kestrel.sql.ast.SelectItem
 import kestrel.sql.ast.SelectStatement
+import kestrel.sql.ast.SetOperationStatement
+import kestrel.sql.ast.SetOperator
 import kestrel.sql.ast.StarProjection
+import kestrel.sql.ast.SubquerySource
+import kestrel.sql.ast.TableSource
 import kestrel.sql.ast.UnaryExpression
+import kestrel.sql.ast.WindowExpression
+import kestrel.sql.ast.WindowFrame
+import kestrel.sql.ast.WindowFunctionKind
+import kestrel.sql.ast.WithQuery
+import kestrel.storage.Collation
+import kestrel.storage.ColumnType
 import kestrel.storage.Row
 import kestrel.storage.Value
-import kestrel.storage.ValueOrdering
+import kestrel.storage.displayWith
+import java.math.BigDecimal
 
 class SelectRunner(private val catalog: Catalog) {
     private val indexPlanner = IndexAccessPlanner(catalog)
+    private val subqueryRunner = SubqueryRunner { select, outer -> run(select, outer) }
+    private val expandingViews = mutableSetOf<String>()
+    private val activeCtes = mutableListOf<CteScope>()
 
-    fun run(statement: SelectStatement): SelectResult {
-        val plan = buildPlan(statement)
+    fun run(statement: SelectStatement, outer: ColumnResolver? = null): SelectResult {
+        val plan = buildPlan(statement, outer)
         val combined = plan.materialize()
         return if (plan.aggregated) plan.aggregate(combined) else plan.projectRows(combined)
     }
 
-    fun explain(statement: SelectStatement): List<String> = buildPlan(statement).describe()
+    fun runQuery(query: QueryStatement, outer: ColumnResolver? = null): SelectResult = when (query) {
+        is SelectStatement -> run(query, outer)
+        is SetOperationStatement -> runSetOperation(query, outer)
+        is WithQuery -> runWith(query, outer)
+    }
 
     private fun buildPlan(statement: SelectStatement): Plan {
         val sources = buildSources(statement)