Establishing a connection to a server requires time and memory from both the client and the server. If you can limit your ODBC connection time or the number of connections to the server, you will reduce the resources your application uses and thereby optimize performance. When you connect to an ODBC data source, you supply file locations, server and user passwords, and sometimes locking information. You supply this information with the connection string, which must be verified and executed each time you access the data file. However, Jet has a built-in connection management capability that caches this information and reuses it as needed. In addition, Jet shares connections whenever possible.
You may therefore want to consider storing your ODBC tables as attached tables in an .mdb file. The only drawback to storing ODBC data this way is that if the ODBC file locations change, you must reestablish a connection to the new data file by dropping and reattaching the tables in the .mdb file.