diff --git a/protocols/protocol_regex.go b/protocols/protocol_regex.go
index 6e788da..49524fd 100644
--- a/protocols/protocol_regex.go
+++ b/protocols/protocol_regex.go
@@ -77,12 +77,18 @@ func Match(scope types.Scope, pattern string, target string) bool {
 	re_any, pres := scope.GetContext(key)
 	if pres {
 		re, _ = re_any.(*regexp.Regexp)
+		if re == nil {
+			return false
+		}
 
 	} else {
 		var err error
 		re, err = regexp.Compile("(?i)" + pattern)
 		if err != nil {
 			scope.Log("Compile regexp: %v", err)
+			// Cache the error to avoid logging again
+			scope.SetContext(key, nil)
+
 			return false
 		}
 
diff --git a/stored.go b/stored.go
index d461d10..e8cac20 100644
--- a/stored.go
+++ b/stored.go
@@ -22,6 +22,7 @@ package vfilter
 
 import (
 	"context"
+	"fmt"
 
 	"github.com/Velocidex/ordereddict"
 	"www.velocidex.com/golang/vfilter/types"
@@ -45,6 +46,12 @@ func NewStoredQuery(query *_Select, name string) *_StoredQuery {
 	}
 }
 
+func (self *_StoredQuery) GoString() string {
+	scope := NewScope()
+	return fmt.Sprintf("StoredQuery{name: %v, query: {%v}, parameters: %v}",
+		self.name, FormatToString(scope, self.query), self.parameters)
+}
+
 func (self *_StoredQuery) Eval(ctx context.Context, scope types.Scope) <-chan Row {
 	output_chan := make(chan Row)
 
diff --git a/types/frozen.go b/types/frozen.go
new file mode 100644
index 0000000..96660d1
--- /dev/null
+++ b/types/frozen.go
@@ -0,0 +1,26 @@
+package types
+
+import (
+	"context"
+)
+
+// A FrozenStoredQuery is a stored query which will be evaluated
+// inside the defined scope instead of the calling scope.
+type FrozenStoredQuery struct {
+	query         StoredQuery
+	defined_scope Scope
+}
+
+func (self FrozenStoredQuery) Query() StoredQuery {
+	return self.query
+}
+
+func (self FrozenStoredQuery) Eval(
+	ctx context.Context, scope Scope) <-chan Row {
+	return self.query.Eval(ctx, self.defined_scope)
+}
+
+func NewFrozenStoredQuery(
+	query StoredQuery, scope Scope) StoredQuery {
+	return &FrozenStoredQuery{query: query, defined_scope: scope}
+}
diff --git a/vfilter.go b/vfilter.go
index 5ddd2a4..678ae2e 100644
--- a/vfilter.go
+++ b/vfilter.go
@@ -466,6 +466,11 @@ type _Select struct {
 	Limit            *int64             `[ LIMIT @Number ]`
 }
 
+func (self *_Select) GoString() string {
+	scope := NewScope()
+	return FormatToString(scope, self)
+}
+
 func (self *_Select) Eval(ctx context.Context, scope types.Scope) <-chan Row {
 	// If the EXPLAIN keyword was used, enabled explaining for this
 	// scope and its children.
diff --git a/visitor.go b/visitor.go
index d00a0cb..89f3b78 100644
--- a/visitor.go
+++ b/visitor.go
@@ -184,6 +184,9 @@ func (self *Visitor) Visit(node interface{}) {
 			self.line_break()
 		}
 
+	case *types.FrozenStoredQuery:
+		self.Visit(t.Query())
+
 	case *_StoredQuery:
 		self.Visit(t.query)