diff --git a/ChangeLog b/ChangeLog
index 4b138a20..17f1cfa1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -22889,3 +22889,7 @@
 	use the CSV generation routines in 'lib/rdcsv.[cpp|h]'.
 2022-02-22 Fred Gleason <fredg@paravelsystems.com>
 	* Added a '--print-progress' switch to rddbmgr(8).
+2022-02-22 Fred Gleason <fredg@paravelsystems.com>
+	* Fixed a bug in rddbmgr(8) that could cause the 346=>347 schema
+	conversion to hang indefinitely with databases containing large
+	cart libraries.
diff --git a/utils/rddbmgr/updateschema.cpp b/utils/rddbmgr/updateschema.cpp
index 328ae80c..135e9e35 100644
--- a/utils/rddbmgr/updateschema.cpp
+++ b/utils/rddbmgr/updateschema.cpp
@@ -10770,9 +10770,17 @@ bool MainObject::UpdateSchema(int cur_schema,int set_schema,QString *err_msg)
       return false;
     }
 
+    sql=QString("create index `CART_IDX` on `STACK_LINES`(`CART`)");
+    if(!RDSqlQuery::apply(sql,err_msg)) {
+      return false;
+    }
     if (!StackLineTitles347(err_msg)) {
       return false;
     }
+    sql=QString("drop index `CART_IDX` on `STACK_LINES`");
+    if(!RDSqlQuery::apply(sql,err_msg)) {
+      return false;
+    }
 
     WriteSchemaVersion(++cur_schema);
   }
@@ -11270,8 +11278,10 @@ bool MainObject::StackLineTitles347(QString *err_msg) const
   while(q->next()) {
     if(!q->value(1).isNull()) {
       sql=QString("update `STACK_LINES` set ")+
-	"`TITLE`='"+RDEscapeString(q->value(1).toString().toLower().replace(" ",""))+"' "+
-	"where `CART`='"+RDEscapeString(q->value(0).toString())+"'";
+	"`TITLE`=\""+
+	RDEscapeString(q->value(1).toString().toLower().replace(" ",""))+"\" "+
+	"where "+
+	QString::asprintf("`CART`=%u",q->value(0).toUInt());
       if(!RDSqlQuery::apply(sql,err_msg)) {
         delete q;
         return false;