I am using an application similar to MS Access and use the ADO engine also. I have a few SQL questions. Please kindly help. 1. Any SQL command for Compressing database, as that supported in MS Access's appliction level? 2. Any SQL command equivalent to "Execute Immediate" command for Oracle? 3. Any SQL command to backup a table in current opened Database to another Database?? 4. I test below SQL command with Substring() / Substr() and get failure. WHY? SELECT Substring(table.field) FROM table a) Has test field in varchar type and text(i.e.memo) type. Both failure. b) Has replace Substring() with Left(). Successful! I very need to use Substring(). How to solve it? Notice: All above questions are asking for SQL command, not Application command SUPER THANKS!