gen4: Support explicit column aliases on derived tables (#14129)

Co-authored-by: Manan Gupta <manan@planetscale.com>

go/vt/vtgate/planbuilder/delete.go

@@ -59,7 +59,6 @@ func gen4DeleteStmtPlanner(
 	if ks, tables := ctx.SemTable.SingleUnshardedKeyspace(); ks != nil {
 		if fkManagementNotRequired(ctx, vschema, tables) {
 			plan := deleteUnshardedShortcut(deleteStmt, ks, tables)
-			plan = pushCommentDirectivesOnPlan(plan, deleteStmt)
 			return newPlanResult(plan.Primitive(), operators.QualifiedTables(ks, tables)...), nil
 		}
 	}

go/vt/vtgate/planbuilder/expression_converter.go

@@ -40,7 +40,7 @@ func booleanValues(astExpr sqlparser.Expr) evalengine.Expr {
 	)
 	switch node := astExpr.(type) {
 	case *sqlparser.Literal:
-		//set autocommit = 'on'
+		// set autocommit = 'on'
 		if node.Type == sqlparser.StrVal {
 			switch strings.ToLower(node.Val) {
 			case "on":
@@ -50,7 +50,7 @@ func booleanValues(astExpr sqlparser.Expr) evalengine.Expr {
 			}
 		}
 	case *sqlparser.ColName:
-		//set autocommit = on
+		// set autocommit = on
 		switch node.Name.Lowered() {
 		case "on":
 			return ON

go/vt/vtgate/planbuilder/filter.go

@@ -17,11 +17,7 @@ limitations under the License.
 package planbuilder
 
 import (
-	"vitess.io/vitess/go/vt/sqlparser"
-	"vitess.io/vitess/go/vt/vterrors"
 	"vitess.io/vitess/go/vt/vtgate/engine"
-	"vitess.io/vitess/go/vt/vtgate/evalengine"
-	"vitess.io/vitess/go/vt/vtgate/planbuilder/plancontext"
 )
 
 type (
@@ -34,38 +30,6 @@ type (
 
 var _ logicalPlan = (*filter)(nil)
 
-func resolveFromPlan(ctx *plancontext.PlanningContext, plan logicalPlan, canPushProjection bool) evalengine.ColumnResolver {
-	return func(expr *sqlparser.ColName) (int, error) {
-		offset, added, err := pushProjection(ctx, &sqlparser.AliasedExpr{Expr: expr}, plan, true, true, false)
-		if err != nil {
-			return 0, err
-		}
-		if added && !canPushProjection {
-			return 0, vterrors.VT13001("column should not be pushed to projection while doing a column lookup")
-		}
-		return offset, nil
-	}
-}
-
-// newFilter builds a new filter.
-func newFilter(ctx *plancontext.PlanningContext, plan logicalPlan, expr sqlparser.Expr) (*filter, error) {
-	predicate, err := evalengine.Translate(expr, &evalengine.Config{
-		ResolveColumn: resolveFromPlan(ctx, plan, false),
-		ResolveType:   ctx.SemTable.TypeForExpr,
-		Collation:     ctx.SemTable.Collation,
-	})
-	if err != nil {
-		return nil, err
-	}
-	return &filter{
-		logicalPlanCommon: newBuilderCommon(plan),
-		efilter: &engine.Filter{
-			Predicate:    predicate,
-			ASTPredicate: expr,
-		},
-	}, nil
-}
-
 // Primitive implements the logicalPlan interface
 func (l *filter) Primitive() engine.Primitive {
 	l.efilter.Input = l.input.Primitive()