Performance tuning Oracle ODAC driver with FetchSize option on OnPremises Data Gateway

To configure the FetchSize setting for the Oracle ODAC 64bit driver used with the Microsoft OnPremises Data Gateway, you can make the changes in the "Microsoft.Mashup.Container.NetFX45.exe.config" file as you mentioned.

To do this, follow these steps:

1. Locate the "Microsoft.Mashup.Container.NetFX45.exe.config" file on the server where the gateway is installed. This file should be in the installation directory of the gateway.

2. Open the file in a text editor.

3. Search for the Oracle connection string in the file. It should look something like this:

   <add name="Oracle" connectionString="Data Source=MyOracleDB;User Id=myUsername;Password=myPassword;" providerName="System.Data.OracleClient" />

4. Add the FetchSize setting to the connection string by appending ";FetchSize=<size>" to the end of the connection string. Replace <size> with the desired fetch size value, which should be a positive integer. For example:

   <add name="Oracle" connectionString="Data Source=MyOracleDB;User Id=myUsername;Password=myPassword;FetchSize=1000;" providerName="System.Data.OracleClient" />

5. Save the changes to the file and restart the OnPremises Data Gateway service to apply the changes.

Note that the fetch size value should be chosen based on the size of the result set and the available memory on the server. A larger fetch size can improve performance by reducing the number of round-trips to the database, but may also increase memory usage.